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Veritas Administration of Veritas InfoScale

Veritas applied sciences to provide executive businesses with information insurance plot and Cloud functions | killexams.com real Questions and Pass4sure dumps

Sep 18, 2018

Stephanie Simone

Veritas applied sciences, issuer of enterprise statistics protection and utility-described storage options, is getting into a government-large settlement for the U.S. typical capabilities Administration (GSA), providing federal agencies with facts governance and cloud statistics management application.

under the contract, executive businesses can Have entry to Veritas records coverage and cloud solutions at negotiated expenditures to permit for more desirable records management.

The agreement is derived from the GSA IT schedule 70 and wholly supports the Federal assistance technology Acquisition Reform Act (FITARA) Enhancement software.

The condense brings Veritas’ enterprise information administration portfolio to every eligible federal, state, native, and tribal govt corporations.

These corporations can build upon the information insurance plot basis of Veritas NetBackup and add additional facts management capabilities to hurry up their cloud initiatives.

probably the most initial choices include:

  • Veritas information perception helps groups enhance unstructured statistics governance to prick back prices, possibility and achieve compliance through actionable intelligence into information possession, usage and entry controls.
  • Veritas eDiscovery Platform provides governments with the choicest evaluation toolkit for separating imperative prison, regulatory and investigative items, revealing context and prioritizing what is most essential, the usage of a single application.
  • Veritas InfoScale helps federal IT teams better protect tips and functions throughout actual and digital infrastructures. InfoScale minimizes downtime with the aid of proposing extreme availability and catastrophe recovery over any distance for essential trade capabilities, together with individual databases, customized purposes and sophisticated multitier functions across physical, virtual and cloud environments.
  • Veritas trade Vault, when offered as a solution with a FedRAMP approved utility-as-a service (SaaS) cloud provider from bluesource (referred to as EV247), frees agencies from the overhead of possessing, operating or managing e mail and file archives. The EV247 retort is powered by means of the realm’s main archiving expertise from Veritas. it's a cloud platform, application archiving solution and managed service multi functional.
  • Veritas 360 records management gives groups the skill to seriously change their facts to handle the challenges of conclusion-to-end records administration by using data visibility, compliance readiness, enterprise continuity, statistics insurance policy and recoverability. It accomplishes every of these dreams whereas holding data/workload portability and storage optimization.
  • For extra tips about this news, consult with www.veritas.com.


    Veritas Enters recent govt-extensive Cloud data administration condense for the U.S. regularly occurring capabilities Administration | killexams.com real Questions and Pass4sure dumps

    Veritas technologies, the worldwide market partake leader within the enterprise records insurance plot and utility-defined storage market, has entered perquisite into a govt-broad condense for the U.S. regular capabilities Administration (GSA) to give federal organizations with facts governance and cloud records administration software.

    below the settlement, executive agencies will Have entry to Veritas data insurance plot and cloud options at negotiated prices to allow for improved statistics management. The settlement is derived from the GSA IT time table 70 and wholly helps the Federal counsel know-how Acquisition Reform Act (FITARA) Enhancement software.

    The condense brings Veritas’ award-profitable trade data administration portfolio to every eligible federal, state, aboriginal and tribal govt agencies. These companies can build upon the records insurance policy groundwork of Veritas NetBackup and add further facts management capabilities to accelerate their cloud initiatives. one of the vital preliminary choices include:

  • Veritas facts insight helps corporations ameliorate unstructured statistics governance to prick back costs, possibility and obtain compliance through actionable intelligence into information possession, usage and entry controls.
  • Veritas eDiscovery Platform provides governments with the most desirable evaluation toolkit for keeping apart principal felony, regulatory and investigative gadgets, revealing context and prioritising what's most critical, the usage of a single application.
  • Veritas InfoScale helps federal IT teams stronger give protection to counsel and functions throughout physical and virtual infrastructures. InfoScale minimises downtime via proposing extreme availability and catastrophe healing over any distance for principal company functions, together with particular person databases, custom applications and complicated multitier purposes throughout physical, virtual and cloud environments.
  • Veritas trade Vault, when offered as a solution with a FedRAMP permitted application-as-a provider (SaaS) cloud carrier from bluesource (called EV247), frees companies from the overhead of possessing, operating or managing electronic mail and file archives. The EV247 retort is powered by means of the realm’s main archiving technology from Veritas. it is a cloud platform, application archiving solution and managed provider multi function.
  • Veritas 360 information administration provides corporations the means to transform their statistics to tackle the challenges of conclusion-to-conclusion statistics management via information visibility, compliance readiness, company continuity, records protection and recoverability. It accomplishes every of these point while retaining statistics/workload portability and storage optimisation.
  • “The IT schedule 70 FITARA Enhancement application will deliver government agencies with greater flexibility in getting access to the ingenious utility solutions they necessity at a better expense to taxpayers,” pointed out Alan Thomas, GSA Federal Acquisition service (FAS) Commissioner. “proposing these solutions via a executive-wide, business-stage condense is an excellent approach to in the reduction of duplication in their procurement manner.”

    “With the upward push of cybercrime, the introduction of recent records laws, an upturn of information enlarge and escalation of digital privateness, federal corporations today necessity to live prepared to accomplish strategic choices round statistics assortment, statistics storage, the location of that records—and the course it can live safeguarded,” mentioned Tom Kennedy, vice chairman and well-known manager, Veritas Public Sector. “because the undisputed leader in data protection and software-described storage, Veritas is offering executive groups light entry to options that succor fight these pressures – to bethink information, hold it included, ameliorate information availability, unencumber the energy of counsel and garner insights to drive advancements in executive programs.”

    –ENDS–

    concerning the IT time table 70 FITARA Enhancement program

    The Federal counsel technology Acquisition Reform Act (FITARA) is a GSA software designed to accomplish it less difficult and extra budget friendly for federal corporations to acquire utility. FITARA became handed with the aid of Congress in 2014 and the workplace of management and funds (OMB) implemented information in 2016. It aims to reduce charges and convey inventive expertise to the federal government.

    About Veritas

    Veritas applied sciences is the leader in the world business facts insurance policy and software-described storage market. We assist essentially the most vital organisations on the planet, together with 86 per cent of the international Fortune 500, lower back up and recuperate their data, retain it cozy and purchasable, safeguard against failure and achieve regulatory compliance. As agencies modernise their IT infrastructure, Veritas promises the know-how that helps them prick back dangers and capitalise on their information. study extra at www.veritas.com or comply with us on Twitter at @veritastechllc.


    Veritas Enters recent executive-huge Cloud facts management Agreeme - wistv.com - Columbia, South Carolina | killexams.com real Questions and Pass4sure dumps

    No influence found, try recent key phrase!Sept. 12, 2018 /PRNewswire/ -- Veritas applied sciences, the worldwide market partake leader within the trade data protection and software-described storage market, has entered perquisite into a govt-extensive agreeme...

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    COMPUTINGFrom...Network World Fusion networking

    January 24, 2000Web posted at: 12:11 p.m. EST (1711 GMT)

    by John Bass and James Robinson, Network World Test Alliance

    (IDG) -- It every boils down to what you're looking for in a network operating system (NOS).

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    The fine news is that there is a NOS waiting just for you. After the rash of recent software revisions, they took an in-depth spy at four of the major NOSes on the market: Microsoft's Windows 2000 Advanced Server, Novell's NetWare 5.1, Red Hat Software's Linux 6.1 and The Santa Cruz Operation's (SCO) UnixWare 7.1.1. Sun declined their invitation to submit Solaris because the company says it's working on a recent version.

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    We create the latest release of Red Hat's commercial Linux bundle led the list for flexibility because its modular design lets you pare down the operating system to suit the assignment at hand. Additionally, you can create scripts out of multiple Linux commands to automate tasks across a distributed environment.

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    The numbers are in

    Regardless of the job you saddle your server with, it has to achieve well at reading and writing files and sending them across the network. They designed two benchmark suites to measure each NOS in these two categories. To reflect the real world, their benchmark tests reckon a wide sweep of server conditions.

    NetWare was the hands-down leader in their performance benchmarking, taking first status in two-thirds of the file tests and earning top billing in the network tests.

    Red Hat Linux followed NetWare in file performance overall and even outpaced the leader in file tests where the read/write loads were small. However, Linux did not achieve well handling great loads - those tests in which there were more than 100 users. Under heavier user loads, Linux had a trend to quit servicing file requests for a short age and then start up again.

    Windows 2000 demonstrated indigent write performance across every their file tests. In fact, they create that its write performance was about 10% of its read performance. After consulting with both Microsoft and Client/Server Solutions, the author of the Benchmark Factory testing appliance they used, they determined that the indigent write performance could live due to two factors. One, which they were unable to verify, might live a feasible performance problem with the SCSI driver for the hardware they used.

    More significant, though, was an issue with their test software. Benchmark Factory sends a write-through flag in each of its write requests that is suppositious to occasions the server to update cache, if appropriate, and then obligate a write to disk. When the write to disk occurs, the write muster is released and the next request can live sent.

    At first glance, it appeared as if Windows 2000 was the only operating system to veneration this write-through flag because its write performance was so poor. Therefore, they ran a second round of write tests with the flag turned off.

    With the flag turned off, NetWare's write performance increased by 30%. This test proved that Novell does indeed veneration the write-through flag and will write to disk for each write request when that flag is set. But when the write-through flag is disabled, NetWare writes to disk in a more efficient manner by batching together contiguous blocks of data on the cache and writing every those blocks to disk at once.

    Likewise, Red Hat Linux's performance increased by 10% to 15% when the write-through flag was turned off. When they examined the Samba file system code, they create that it too honors the write-through flag. The Samba code then finds an optimum time during the read/write sequence to write to disk.

    This second round of file testing proves that Windows 2000 is conditional on its file system cache to optimize write performance. The results of the testing with the write-through flag off were much higher - as much as 20 times faster. However, Windows 2000 silent fell behind both NetWare and RedHat Linux in the file write tests when the write-through flag was off.

    SCO honors the write-through flag by default, since its journaling file system is constructed to maximize data integrity by writing to disk for every write requests. The results in the write tests with the write-through flag on were very similar to the test results with the write-through flag turned off.

    For the network benchmark, they developed two tests. Their long TCP transaction test measured the bandwidth each server can sustain, while their short TCP transaction test measured each server's skill to handle great numbers of network sessions with diminutive file transactions.

    Despite a indigent showing in the file benchmark, Windows 2000 came out on top in the long TCP transaction test. Windows 2000 is the only NOS with a multithreaded IP stack, which allows it to handle network requests with multiple processors. Novell and Red Hat whine they are working on integrating this capability into their products.

    NetWare and Linux too registered tenacious long TCP test results, coming in second and third, respectively.

    In the short TCP transaction test, NetWare came out the transparent winner. Linux earned second status in spite of its lack of champion for abortive TCP closes, a fashion by which an operating system can quickly split down TCP connections. Their testing software, Ganymede Software's Chariot, uses abortive closes in its TCP tests.

    Moving into management

    As enterprise networks grow to require more servers and champion more quit users, NOS management tools become crucial elements in keeping networks under control. They looked at the management interfaces of each product and drilled down into how each handled server monitoring, client administration, file and print management, and storage management.

    We create Windows 2000 and NetWare provide equally useful management interfaces.

    Microsoft Management Console (MMC) is the glue that holds most of the Windows 2000 management functionality together. This configurable graphical user interface (GUI) lets you snap in Microsoft and third-party applets that customize its functionality. It's a two-paned interface, much dote Windows Explorer, with a nested list on the left and selection details on the right. The console is light to consume and lets you configure many local server elements, including users, disks, and system settings such as time and date.

    MMC too lets you implement management policies for groups of users and computers using dynamic Directory, Microsoft's recent directory service. From the dynamic Directory management appliance inside MMC, you can configure users and change policies.

    The network configuration tools are create in a sunder application that opens when you click on the Network Places icon on the desktop. Each network interface is listed inside this window. You can add and change protocols and configure, enable and disable interfaces from here without rebooting.

    NetWare offers several interfaces for server configuration and management. These tools offer duplicate functionality, but each is useful depending from where you are trying to manage the system. The System Console offers a number of tools for server configuration. One of the most useful is NWConfig, which lets you change start-up files, install system modules and configure the storage subsystem. NWConfig is simple, intuitive and predictable.

    ConsoleOne is a Java-based interface with a few graphical tools for managing and configuring NetWare. Third-party administration tools can plug into ConsoleOne and let you manage multiple services. They deem ConsoleOne's interface is a bit unsophisticated, but it works well enough for those who must Have a Windows- based manager.

    Novell too offers a Web-accessible management application called NetWare Management Portal, which lets you manage NetWare servers remotely from a browser, and NWAdmin32, a relatively simple client-side appliance for administering Novell Directory Services (NDS) from a Windows 95, 98 or NT client.

    Red Hat's overall systems management interface is called LinuxConf and can race as a graphical or text-based application. The graphical interface, which resembles that of MMC, works well but has some layout issues that accomplish it difficult to consume at times. For example, when you race a setup application that takes up a lot of the screen, the system resizes the application larger than the desktop size.

    Still, you can manage pretty much anything on the server from LinuxConf, and you can consume it locally or remotely over the Web or via telnet. You can configure system parameters such as network addresses; file system settings and user accounts; and set up add-on services such as Samba - which is a service that lets Windows clients Get to files residing on a Linux server - and FTP and Web servers. You can apply changes without rebooting the system.

    Overall, Red Hat's interface is useful and the underlying tools are powerful and flexible, but LinuxConf lacks the polish of the other vendors' tools.

    SCO Admin is a GUI-based front quit for about 50 SCO UnixWare configuration and management tools in one window. When you click on a tool, it brings up the application to manage that detail in a sunder window.

    Some of SCO's tools are GUI-based while others are text-based. The server required a reboot to apply many of the changes. On the plus side, you can manage multiple UnixWare servers from SCOAdmin.

    SCO too offers a useful Java-based remote administration appliance called WebTop that works from your browser.

    An eye on the servers and clients

    One principal administration assignment is monitoring the server itself. Microsoft leads the pack in how well you can retain an eye on your server's internals.

    The Windows 2000 System Monitor lets you view a real-time, running graph of system operations, such as CPU and network utilization, and reminiscence and disk usage. They used these tools extensively to determine the upshot of their benchmark tests on the operating system. Another appliance called Network Monitor has a basic network packet analyzer that lets you behold the types of packets coming into the server. Together, these Microsoft utilities can live used to compare performance and capacity across multiple Windows 2000 servers.

    NetWare's Monitor utility displays processor utilization, reminiscence usage and buffer utilization on a local server. If you know what to spy for, it can live a powerful appliance for diagnosing bottlenecks in the system. Learning the significance of each of the monitored parameters is a bit of a challenge, though.

    If you want to spy at performance statistics across multiple servers, you can tap into Novell's Web Management Portal.

    Red Hat offers the measure Linux command-line tools for monitoring the server, such as iostat and vmstat. It has no graphical monitoring tools.

    As with any Unix operating system, you can write scripts to automate these tools across Linux servers. However, these tools are typically cryptic and require a tall smooth of proficiency to consume effectively. A suite of graphical monitoring tools would live a mighty addition to Red Hat's Linux distribution.

    UnixWare too offers a number of monitoring tools. System Monitor is UnixWare's simple but limited GUI for monitoring processor and reminiscence utilization. The sar and rtpm command-line tools together list real-time system utilization of buffer, CPUs and disks. Together, these tools give you a fine overall conception of the load on the server.

    Client administration

    Along with managing the server, you must manage its users. It's no dumbfound that the two NOSes that ship with an integrated directory service topped the realm in client administration tools.

    We were able to configure user permissions via Microsoft's dynamic Directory and the directory administration appliance in MMC. You can group users and computers into organizational units and apply policies to them.

    You can manage Novell's NDS and NetWare clients with ConsoleOne, NWAdmin or NetWare Management Portal. Each can create users, manage file space, and set permissions and rights. Additionally, NetWare ships with a five-user version of Novell's ZENworks tool, which offers desktop administration services such as hardware and software inventory, software distribution and remote control services.

    Red Hat Linux doesn't offer much in the course of client administration features. You must control local users through Unix permission configuration mechanisms.

    UnixWare is similar to Red Hat Linux in terms of client administration, but SCO provides some Windows binaries on the server to remotely set file and directory permissions from a Windows client, as well as create and change users and their settings. SCO and Red Hat offer champion for the Unix-based Network Information Service (NIS). NIS is a store for network information dote logon names, passwords and home directories. This integration helps with client administration.

    Handling the staples: File and print

    A NOS is nothing without the skill to partake file storage and printers. Novell and Microsoft collected top honors in these areas.

    You can easily add and maintain printers in Windows 2000 using the print administration wizard, and you can add file shares using dynamic Directory management tools. Windows 2000 too offers Distributed File Services, which let you combine files on more than one server into a single share.

    Novell Distributed Print Services (NDPS) let you quickly incorporate printers into the network. When NDPS senses a recent printer on the network, it defines a Printer Agent that runs on the printer and communicates with NDS. You then consume NDS to define the policies for the recent printer.

    You define NetWare file services by creating and then mounting a disk volume, which too manages volume policies.

    Red Hat includes Linux's printtool utility for setting up server-connected and networks printers. You can too consume this GUI to create printcap entries to define printer access.

    Linux has a set of command-line file system configuration tools for mounting and unmounting partitions. Samba ships with the product and provides some integration for Windows clients. You can configure Samba only through a cryptic configuration ASCII file - a earnest drawback.

    UnixWare provides a supple GUI-based printer setup appliance called Printer SetUp Manager. For file and volume management, SCO offers a appliance called VisionFS for interoperability with Windows clients. They used VisionFS to allow their NT clients to access the UnixWare server. This service was light to configure and use.

    Storage management

    Windows 2000 provides the best tools for storage management. Its graphical Manage Disks appliance for local disk configuration includes software RAID management; you can dynamically add disks to a volume set without having to reboot the system. Additionally, a signature is written to each of the disks in an array so that they can live moved to another 2000 server without having to configure the volume on the recent server. The recent server recognizes the drives as members of a RAID set and adds the volume to the file system dynamically.

    NetWare's volume management tool, NWConfig, is light to use, but it can live a tiny confusing to set up a RAID volume. Once they knew what they were doing, they had no problems formatting drives and creating a RAID volume. The appliance looks a tiny primitive, but they give it tall marks for functionality and ease of use.

    Red Hat Linux offers no graphical RAID configuration tools, but its command line tools made RAID configuration easy.

    To configure disks on the UnixWare server, they used the Veritas Volume Manager graphical disk and volume administration appliance that ships with UnixWare. They had some problems initially getting the appliance to recognize the drives so they could live formatted. They managed to labor around the disk configuration problem using an assortment of command line tools, after which Volume Manager worked well.

    Security

    While they did not probe these NOSes extensively to expose any security weaknesses, they did spy at what they offered in security features.

    Microsoft has made significant strides with Windows 2000 security. Windows 2000 supports Kerberos public key certificates as its primary authentication mechanism within a domain, and allows additional authentication with smart cards. Microsoft provides a Security Configuration appliance that integrates with MMC for light management of security objects in the dynamic Directory Services system, and a recent Encrypting File System that lets you designate volumes on which files are automatically stored using encryption.

    Novell added champion for a public-key infrastructure into NetWare 5 using a public certificate schema developed by RSA Security that lets you tap into NDS to generate certificates.

    Red Hat offers a basic Kerberos authentication mechanism. With Red Hat Linux, as with most Unix operating systems, the network services can live individually controlled to enlarge security. Red Hat offers Pluggable Authentication Modules as a course of allowing you to set authentication policies across programs running on the server. Passwords are protected with a shadow file. Red Hat too bundles firewall and VPN services.

    UnixWare has a set of security tools called Security Manager that lets you set up varying degrees of intrusion protection across your network services, from no restriction to turning every network services off. It's a fine management time saver, though you could manually modify the services to achieve the very result.

    Stability and weakness tolerance

    The most feature-rich NOS is of tiny value if it can't retain a server up and running. Windows 2000 offers software RAID 0, 1 and 5 configurations to provide weakness tolerance for onboard disk drives, and has a built-in network load-balancing feature that allows a group of servers to spy dote one server and partake the very network cognomen and IP address. The group decides which server will service each request. This not only distributes the network load across several servers, it too provides weakness tolerance in case a server goes down. On a lesser scale, you can consume Microsoft's Failover Clustering to provide basic failover services between two servers.

    As with NT 4.0, Windows 2000 provides reminiscence protection, which means that each process runs in its own segment.

    There are too backup and restore capabilities bundled with Windows 2000.

    Novell has an add-on product for NetWare called Novell Cluster Services that allows you to cluster as many as eight servers, every managed from one location using ConsoleOne, NetWare Management Portal or NWAdmin32. But Novell presently offers no clustering products to provide load balancing for applications or file services. NetWare has an complicated reminiscence protection scheme to segregate the reminiscence used for the kernel and applications, and a Storage Management Services module to provide a highly supple backup and restore facility. Backups can live all-inclusive, cover parts of a volume or store a differential snapshot.

    Red Hat provides a load-balancing product called piranha with its Linux. This package provides TCP load balancing between servers in a cluster. There is no arduous limit to the number of servers you can configure in a cluster. Red Hat Linux too provides software RAID champion through command line tools, has reminiscence protection capabilities and provides a rudimentary backup facility.

    SCO provides an optional feature to cluster several servers in a load-balancing environment with Non-Stop Clustering for a tall smooth of fault-tolerance. Currently, Non-Stop Clustering supports six servers in a cluster. UnixWare provides software RAID champion that is managed using SCO's On-Line Data Manager feature. every the measure RAID levels are supported. Computer Associates' bundled ArcServeIT 6.6 provides backup and restore capabilities. UnixWare has reminiscence protection capabilities.

    Documentation

    Because their testing was conducted before Windows 2000's common availability ship date, they were not able to evaluate its hard-copy documentation. The online documentation provided on a CD is extensive, useful and well-organized, although a Web interface would live much easier to consume if it gave more than a pair of sentences at a time for a particular succor topic.

    NetWare 5 comes with two manuals: a detailed manual for installing and configuring the NOS with fine explanations of concepts and features along with an overview of how to configure them, and a diminutive spiral-bound booklet of quick start cards. Novell's online documentation is very helpful.

    Red Hat Linux comes with three manuals - an installation guide, a getting started pilot and a reference manual - every of which are light to follow.

    Despite being the most difficult product to install, UnixWare offers the best documentation. It comes with two manuals: a system handbook and a getting started guide. The system handbook is a reference for conducting the installation of the operating system. It does a fine job of reflecting this painful experience. The getting started pilot is well-written and well-organized. It covers many of the tools needed to configure and maintain the operating system. SCO's online documentation looks nice and is light to follow.

    Wrapping up

    The bottom line is that these NOSes offer a wide sweep of characteristics and provide enterprise customers with a mighty deal of altenative regarding how each can live used in any given corporate network.

    If you want a good, common purpose NOS that can deliver enterprise-class services with every the bells and whistles imaginable, then Windows 2000 is the strongest contender. However, for tall performance, enterprise file and print services, their tests define that Novell leads the pack. If you're willing to pay a higher expense for scalability and reliability, SCO UnixWare would live a safe bet. But if you necessity an inexpensive alternative that will give you bare-bones network services with decent performance, Red Hat Linux can certainly suitable the bill.

    The altenative is yours.

    Bass is the technical director and Robinson is a senior technical staff member at Centennial Networking Labs (CNL) at North Carolina status University in Raleigh. CNL focuses on performance, capacity and features of networking and server technologies and equipment.

    RELATED STORIES:

    Debate will focus on Linux vs. LinuxJanuary 20, 2000Some Windows 2000 PCs will jump the gunJanuary 19, 2000IBM throws Linux lovefestJanuary 19, 2000Corel Linux will race Windows appsJanuary 10, 2000Novell's eDirectory spans platformsNovember 16, 1999New NetWare embraces Web appsNovember 2, 1999Microsoft sets a date for Windows 2000October 28, 1999

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    Fusion's Forum: Square off with the vendors over who has the best NOS(Network World Fusion)How they did it: Details of the testing(Network World Fusion)Find out the tuning parameters(Network World Fusion)Download the Config files(Network World Fusion)The Shootout results(Network World Fusion)Fusion's NOS resources(Network World Fusion)With Windows 2000, NT grows up(Network World Fusion)Fireworks expected at NOS showdown(Network World Fusion)

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    Symantec NetBackup Adds intelligent Policy Technology to Automatically discover and Protect Virtual Machines | killexams.com real questions and Pass4sure dumps

    MOUNTAIN VIEW, CA--(Marketwire - 03/15/11) - Symantec Corp. (NASDAQ:SYMC - News) today announced enhancements to NetBackup 7 that simplify data protection in virtual environments. The latest release introduces Virtual Machine intelligent Policy technology for VMware environments to automate the discovery and protection of virtual machines while enforcing existing data protection policies. Unlike other data protection solutions, this technology will accelerate the transition to a virtual environment for enterprise organizations deploying a great number of virtual machines or edifice a private cloud infrastructure."Virtualization has changed how organizations back up data, and NetBackup continues to evolve to protect their customers' information within virtual environments," said Brian Dye, vice president of product management, Symantec NetBackup. "NetBackup 7 eases the management of protecting and recovering data within physical and virtual environments through a single solution, while reducing data stores with integrated deduplication at the source or media server using NetBackup or NetBackup appliances."Click to Tweet: Symantec @NetBackup expands award-winning champion for virtual and physical machines with a single solution: http://bit.ly/eZPhBwFor deeper dive into what's recent with NetBackup 7, read the following blog post:

    In addition to award-winning champion for virtual machines, NetBackup 7 delivers simplified reporting, faster disaster recovery when using NetBackup deduplication, and further supports Oracle and MySQL database applications. Symantec too offers an light "one-step" upgrade to NetBackup 7 from older versions, including NetBackup 6.0 and 6.5 to meet the needs of its customers. Symantec NetBackup appliances provide organizations with a fleet and proven alternative to upgrade their environment to NetBackup 7.New Features and Benefits:

  • A faster path to the virtual datacenter: Virtual Machine intelligent Policy technology adds automation to the discovery and protection of virtual machines and minimizes the administration endeavor required for tall performance VMware virtual machine backups through greater awareness of VMware vSphere® resource usage.
  • 50 Percent Faster Virtual Machine Backup: Patented Granular Recovery Technology (GRT), which supports instant file or folder recovery from virtual machine image backups, is now available for Linux systems in VMware environments. This allows customers to reduce comparable virtual machine backup times by up to 50 percent, simplify administration and ameliorate the hurry of recovery for individual files.
  • On-Demand Recovery From Anywhere: recent auto image replication technology allows customers who replicate data between multiple sites or NetBackup domains to accomplish the backup data at an alternate site instantly available to NetBackup for faster disaster recovery.
  • Accelerate Recovery: NetBackup RealTime, which provides customers with continuous data protection, now supports VMware environments to eradicate the backup window, reduce impact for very great VMware hosts and enable near-instant recovery of entire systems.
  • Meet Compliance and Regulatory Requirements: NetBackup 7 now has greater audit trail capabilities to succor backup administrators champion compliance and regulatory requirements.
  • Central Control: NetBackup OpsCenter, which delivers a single management view of any Symantec data protection environment, adds improved reports for storage lifecycle policies, audit trails and licensing. recent tools, such as the workload analyzer, allow customers to better tailor operations to maximize hardware usage.
  • Deduplication for Oracle: Enhanced Oracle database agent further improves backup and deduplication performance.
  • MySQL Support: NetBackup adds a recent agent to centralize and automate backup and recovery of MySQL databases.
  • Client Upgrades Simplified: Improvements to the LiveUpdate capability allow client upgrades for UNIX, Linux and Windows from version NetBackup 6.5 and later from a single policy controlled by the NetBackup administrator.
  • Related

    Connect with Symantec

    About Storage from Symantec Symantec helps organizations secure and manage their information-driven world with storage management, email archiving and backup & recovery solutions.About Symantec Symantec is a global leader in providing security, storage and systems management solutions to succor consumers and organizations secure and manage their information-driven world. Their software and services protect against more risks at more points, more completely and efficiently, enabling confidence wherever information is used or stored. More information is available at www.symantec.com.NOTE TO EDITORS: If you would dote additional information on Symantec Corporation and its products, gratify visit the Symantec news scope at http://www.symantec.com/news. every prices illustrious are in U.S. dollars and are telling only in the United States.Symantec and the Symantec Logo are trademarks or registered trademarks of Symantec Corporation or its affiliates in the U.S. and other countries. Other names may live trademarks of their respective owners.


    More About Filesystems | killexams.com real questions and Pass4sure dumps

    This chapter is from the bespeak 

    If they reckon filesystems as a mechanism for both storing and locating data, then the two key elements for any filesystem are the items being stored and the list of where those items are. The deeper details of how a given filesystem manipulates its data and meta-information go beyond the scope of this chapter but are addressed further in Appendix B, "Anatomy of a Filesystem."

    Filesystem Components That the Admin Needs to Know About

    As always, they necessity to Get a handle on the vocabulary before they can understand how the elements of a filesystem labor together. The next three sections recount the basic components with which you, as a sysadmin, necessity to live familiar.

    Files

    The most intuitively obvious components of a filesystem are, of course, its files. Because everything in UNIX is a file, special functions are differentiated by file type. There are fewer file types than you might imagine, as Table 3.2 shows.

    Table 3.2 File Types and Purposes, with Examples

    File Type

    Purpose/Contents

    Examples

    Directory

    Maintains information for directory structure

    /

    /usr

    /etc

    Block special

    Buffered device file

    Linux: /dev/hda1

    Solaris: /dev/dsk/c0t0d0s0

    Character special

    Raw device file

    Linux: /dev/tty0

    Solaris: /dev/rdsk/c0t0d0s0

    UNIX domain socket

    Interprocess communication (IPC)

    See output of commands for files Linux: netstat –x Solaris: netstat -f unix

    Named pipe special (FIFO device)

    First-in-first-out IPC mechanism, Invoked by name

    Linux: /dev/initctl Solaris: /etc/utmppipe/etc/cron.d/FIFO

    Symbolic link

    Pointer to another file (any type)

    /usr/tmp -> ../var/tmp

    Regular

    All other files; holds data of every other types

    Text files object files Database files Executables/binaries

    Notice that directories are a kind of file. The key is that they Have a specific kind of format and contents (see Appendix B for more details). A directory holds the filenames and index numbers (see the following section, "Inodes") of every its constituent files, including subdirectories.

    Directory files are not flat (or regular) files, but are indexed (like a database), so that you can silent locate a file quickly when you Have a great number of files in the very directory.13

    Even though file handling is generally transparent, it is principal to bethink that a file's data blocks14 may not live stored sequentially (or even in the very common disk region). When data blocks are widely scattered in an uncoordinated manner, it can impress access times and enlarge I/O overhead.

    Inodes

    Meta-information about files is stored in structures called index nodes, or inodes. Their contents vary based on the particular filesystem in use, but every inodes hold the following information about the file they index:15

  • Inode identification number

  • File type

  • Owners: user and group

  • UNIX permissions

  • File size

  • Timestamps

  • ctime: final file status change time

  • mtime: final data modification time16

  • atime: final access time

  • Reference/link count

  • Physical location information for data blocks

  • Notice that the filename is not stored in the inode, but as an entry in the file's closest parent directory.

    All other information about a file that ls displays is stored in an inode somewhere. With a few handy options, you can tug out lots of useful information. Let's whine that you want to know the inode number of the Solaris kernel.17 You just give the –i option, and voilá:

    [sun:10 ~]ls -i /kernel/genunix

    264206 genunix

    Of course, ls –l is an old-fashioned friend, telling you most everything that you want to know. Looking at the Solaris kernel again, you Get the output in figure 3.4.

    Figure 3.4 Diagrammed Output of ls on a File

    Notice that the timestamp shown by default in a long listing is mtime. You can pass various options to ls to view ctime and atime instead. For other nifty permutations, behold the ls man page.

    File Permissions and Ownership Refresher

    Because UNIX was designed to champion many users, the question naturally arises how to know who can behold what files. The first and simplest retort is simply to permit users to examine only their own files. This, of course, would accomplish it difficult, if not impossible, to share, creating mighty difficulties in collaborative environments and causing a string of other problems: Why can't I race ls? Because the system created it, not you, is only the most obvious illustration of such problems.

    Users and Groups

    UNIX uses a three-part system to determine file access: There's what you, as the file owner, are allowed to do; there's what the group is allowed to do; and there's what other people are allowed to do. Let's behold what Elvis's permissions spy like:

    [ elvis@frogbog elvis ]$ ls -l

    total 36

    drwxr-xr-x 5 elvis users 4096 Dec 9 21:55 Desktop

    drwxr-xr-x 2 elvis users 4096 Dec 9 22:00 Mail

    -rw-r--r-- 1 elvis users 36 Dec 9 22:00 README

    -rw-r--r-- 1 elvis users 22 Dec 9 21:59 ThisFile

    drwxr-xr-x 2 elvis users 4096 Dec 12 19:57 arc

    drwxr-xr-x 2 elvis users 4096 Dec 10 00:40 songs

    -rw-r--r-- 1 elvis users 46 Dec 12 19:52 tao.txt

    -rw-r--r-- 1 elvis users 21 Dec 9 21:59 thisfile

    -rw-r--r-- 1 elvis users 45 Dec 12 19:52 west.txt

    As long as we're here, let's crack down exactly what's being displayed. First, they Have a 10-character string of letters and hyphens. This is the representation of permissions, which I'll crack down in a minute. The second detail is a number, usually a single digit. This is the number of arduous links to that directory. I'll argue this later in this chapter. The third thing is the username of the file owner, and the fourth is the cognomen of the file's group. The fifth column is a number representing the size of the file, in bytes. The sixth contains the date and time of final modification for the file, and the final column shows the filename.

    Every user on the system has a username and a number that is associated with that user. This number generally is referred to as the UID, short for user ID. If a user has been deleted but, for some reason, his files remain, the username is replaced with that user's UID. Similarly, if a group is deleted but silent owns files, the GID (group number) shows up instead of a cognomen in the group field. There are too other circumstances in which the system can't correlate the cognomen and the number, but these should live relatively rare occurrences.

    As a user, you can't change the owner of your files: This would open up some earnest security holes on the system. Only root can chown files, but if he makes a mistake, you can now inquire of root to chown the files to you. As a user, you can chgrp a file to a different group of which you are a member. That is, if Elvis is a member of a group named users and a group named elvis, he can chgrp elvis west.txt or chgrp users west.txt, but because he's not a member of the group beatles, he can't chgrp beatles west.txt. A user can belong to any number of groups. Generally (although this varies to some extent by flavor), files created belong to the group to which the directory belongs. On most modern UNIX variants, the group that owns files is whatever group is listed as your primary group by the system in the /etc/passwd file and can live changed via the newgrp command. On these systems, Elvis can chgrp users if he wants his files to belong to the users group, or he can chgrp elvis if he wants his files to belong to the elvis group.

    Reading Permissions

    So, what were those silly strings of letters and hyphens at the nascence of each long directory listing? I already said that they represented the permissions of the file, but that's not especially helpful. The 10 characters of that string limn the permission bits for each file. The first character is separate, and the final nine are three very similar groups of three characters. I'll define each of these in turn.

    If you spy back to Elvis's long listing of his directory, you'll behold that most of the files simply Have a hyphen as the first character, whereas several possess a d in this field. The more astute reader might note that the files with a d in that first realm every betide to live directories. There's a fine understanding for this: The first permissions character denotes whether that file is a special file of one sort or another.

    What's a special file? It's either something that isn't really a file (in the sense of a sequential stream of bytes on a disk) but that UNIX treats as a file, such as a disk or a video display, or something that is really a file but that is treated differently. A directory, by necessity, is a stream of bytes on disk, but that d means that it's treated differently.

    The next three characters limn what the user who owns the file can finish with it. From left to right, these permissions are read, write, and execute. Read permission is just that—the capability to behold the contents of a file. Write permission implies not only the perquisite to change the contents of a file, but too the perquisite to delete it. If I finish not possess write permission to a file, rm not_ permitted.txt fails.

    Execute permission determines whether the file is too a command that can live race on the system. Because UNIX sees everything as a file, every commands are stored in files that can live created, modified, and deleted dote any other file. The computer then needs a course to relate what can and can't live run. The execute bit does this.

    Another principal understanding that you necessity to worry about whether a file is executable is that some programs are designed to live race only by the system administrator: These programs can modify the computer's configuration or can live risky in some other way. Because UNIX enables you to specify permissions for the owner, the group, and other users, the execute bit enables the administrator to restrict the consume of risky programs.

    Directories handle the execute permission differently. If a directory does not Have execute permissions, that user (or group, or other users on the system) can't cd into that directory and can't spy at information about the files in that directory. (You usually can find the names of the files, however.) Even if you Have permissions for the files in that directory, you generally can't spy at them. (This varies to some extent by platform.)

    The second set of three characters is the group permissions (read, write, and execute, in that order), and the final set of three characters is what other users on the system are permitted to finish with that file. Because of security concerns (either due to other users on your system or due to pervasive networks such as the Internet), giving write access to other users is highly discouraged.

    Changing Permissions

    Great, you can now read the permissions in the directory listing, but what can you finish with them? Let's whine that Elvis wants to accomplish his directory readable only by himself. He can chmod go-rwx ~/songs: That means remove the read, write, and execute permissions for the group and others on the system. If Elvis decides to let Nashville artists bewitch a spy at his material but not change it (and if there's a group nashville on the system), he can first chgrp nashville songs and then chmod g+r songs.

    If Elvis does this, however, he'll find that (at least, on some platforms) members of group nashville can't spy at them. Oops! With a simple chmod g+x songs, the problem is solved:

    [ elvis@frogbog elvis ]$ ls -l

    total 36

    drwxr-xr-x 5 elvis users 4096 Dec 9 21:55 Desktop

    drwxr-xr-x 2 elvis users 4096 Dec 9 22:00 Mail

    -rw-r--r-- 1 elvis users 36 Dec 9 22:00 README

    -rw-r--r-- 1 elvis users 22 Dec 9 21:59 ThisFile

    drwxr-xr-x 2 elvis users 4096 Dec 12 19:57 arc

    drwxr-x--- 2 elvis nashvill 4096 Dec 15 14:21 songs

    -rw-r--r-- 1 elvis users 46 Dec 12 19:52 tao.txt

    -rw-r--r-- 1 elvis users 21 Dec 9 21:59 thisfile

    -rw-r--r-- 1 elvis users 45 Dec 12 19:52 west.txt

    Special Permissions

    In addition to the read, write, and execute bits, there exists special permissions used by the system to determine how and when to suspend the regular permission rules. Any thorough understanding of UNIX requires an understanding of the setuid, setgid, and sticky bits. For regular system users, only a common understanding of these is necessary, and this discussion is thus brief. fine documentation on this topic exists elsewhere for budding system administrators and programmers.

    setuid

    The setuid bit applies only to executable files and directories. In the case of executable programs, it means that the given program runs as though the file owner were running it. That is, xhextris, a variant on Tetris, has the following permissions on my system:

    -rwsr-xr-x

    1 games games 32516 May 18 1999 /usr/X11R6/bin/xhextris

    There's a pseudouser called games on the system, which can't live logged into and has no home directory. When the xhextris program executes, it can read and write to files that only the game's pseudouser normally would live permitted. In this case, there's a high-score file stored on the system that writeable only by that user. When Elvis runs the game, the system acts as though he were the user games, and thus he is able to store the high-score file. To set the setuid bit on a file, you can relate chmod to give it mode u+s. (You can deem of this as uid set, although this isn't technically accurate.)

    setgid

    The setgid bit, which stands for "set group id," works almost identically to setuid, except that the system acts as though the user's group is that of the given file. If xhextris had used setgid games instead of setuid games, the tall score would live writeable to any directory owned by the group games. It is used by the system administrator in ways fundamentally similar to the setuid permission.

    When applied to directories on Linux, Irix, and Solaris (and probably most other POSIX-compliant UNIX flavors as well), the setgid bit means that recent files are given the parent directory's group rather than the user's primary or current group. This can live useful for, say, a directory for fonts built by (and for) a given program. Any user might generate the fonts via a setgid command that writes to a setgid directory. setgid on directories varies by platform; check your documentation. To set the setgid bit, you can relate chmod to consume g+s (gid set).

    sticky

    Although a file in a group or world-writeable directory without the sticky bit can live deleted by anyone with write permission for that directory (user, group, or other), a file in a directory with the sticky bit set can live deleted only by either the file's owner or root. This is particularly useful for creating temporary directories or scratch space that can live used by anyone without one's files being deleted by others. You can set permission +t in chmod to give something the sticky bit.

    Numeric Permissions

    Like almost everything else on UNIX, permissions Have a number associated with them. It's generally considered that permissions are a group of four digits, each between 0 and 7. Each of those digits represents a group of three permissions, each of which is a yes/no answer. From left to right, those digits limn special permissions, user permissions, group permissions, and other permissions.

    So, About Those permission Bits...

    Most programs reading permission bits hope four digits, although often only three are given. Shorter numbers are filled in with leading zeros: 222 is treated as 0222, and 5 is treated as 0005. The three rightmost digits are, as previously mentioned, user (owner) permissions, group permissions, and other permissions, from perquisite to left.

    Each of these digits is calculated in the following manner: read permission has a value of 4, write permission has a value of 2, and execute permission has a value of 1. Simply add these values together, and you've got that permission value. Read, write, and execute would live 7, read and write without execute would live 6, and no permission to finish anything would live 0. Read, write, and execute for the file owner, with read and execute for the group and nothing at every for anyone else, would live 750. Read and write for the user and group, but only read for others, would live 664.

    The special permissions are 4 for setuid, 2 for setgid, and 1 for sticky. This digit is prepended to the three-digit numeric permission: A temporary directory with sticky read, write, and execute permission for everyone would live mode 1777. A setuid root directory writeable by nobody else would live 4700. You can consume chmod to set numeric permissions directly, as in chmod 1777 /tmp.

    umask

    In addition to a more precise consume of chmod, numeric permissions are used with the umask command, which sets the default permissions. More precisely, it "masks" the default permissions: The umask value is subtracted from the maximum feasible settings.* umask deals only with the three-digit permission, not the full-fledged four-digit value. A umask of 002 or 022 is most commonly the default. 022, subtracted from 777, is 755: read, write, and execute for the user, and read and execute for the group and others. 002 from 777 is 775: read, write, and execute for the user and group, and read and execute for others. I attend to set my umask to 077: read, write, and execute for myself, and nothing for my group or others. (Of course, when working on a group project, I set my umask to 007: My group and I can read, write, or execute anything, but others can't finish anything with their files.)

    You should note that the umask assumes that the execute bit on the file will live set. every umasks are subtracted from 777 rather than 666, and those extra ones are subtracted later, if necessary. (See Appendix B for more details on permission bits and umask workings.)

    *Actually, the permission bits are XORed with the maximum feasible settings, if you're a computer science type.

    Also notice that the first bit of output prepended to the permissions string indicates the file type. This is one handy course of identifying a file's type. Another is the file command, as shown in Table 3.3.

    Table 3.3 ls File Types and file Output Sample

    File Type

    ls File kind Character

    File panoply Example

    Directory

    d

    [either:1 ~]file /usr/usr: directory

    Block special device

    b

    [linux: 10 ~] file /dev/hda1/dev/hda1: obscure special (3/1)[sun:10 root ~]file /dev/dsk/c0t0d0s0/dev/dsk/c0t0d0s0: obscure special(136/0)

    Character special device

    c

    [linux:11 ~] file /dev/tty0/dev/tty0: character special (4/0)

    [ensis:11 ~]file /dev/rdsk/c0t0d0s0/dev/rdsk/c0t0d0s0: character special (136/0)

    UNIX domain socket

    s

    [linux:12 ~] file /dev/log/dev/log: socket

    [sun:12 ~]file /dev/ccv/dev/ccv: socket

    Named pipe special (FIFO device)

    p

    [linux:13 ~] file /dev/initctl/dev/initctl: fifo (named pipe)

    [sun:13 ~]file /etc/utmppipe/etc/utmppipe: fifo

    Symbolic link

    l

    [linux:14 ~] file /usr/tmp/usr/tmp: symbolic link to ../var/tmp

    [sun:14 ~]file -h /usr/tmp/usr/tmp: symbolic link to ¬../var/tmp

    Regular

    -

    [linux:15 ~] file /etc/passwd/etc/passwd: ASCII text

    [linux:15 ~] file /boot/vmlinux-2.4.2-2/boot/vmlinux-2.4.2-2: ELF 32-bit LSB executable,

    ¬Intel 80386, version 1,statically linked, not stripped

    [linux:15 ~] file /etc/rc.d/init.d/sshd/etc/rc.d/init.d/sshd: Bourne-Again shell script text executable

    [sun:15 ~]file /etc/passwd

    /etc/passwd: ascii text

    [sun:15 ~]file /kernel/genunix

    -/kernel/genunix: ELF 32-bit MSB relocatable

    ¬SPARC Version 1

    [sun:15 ~]file /etc/init.d/sshd

    /etc/init.d/sshd: executable

    ¬/sbin/sh script

    Notice the in-depth information that file gives—in many cases, it shows details about the file that no other command will readily panoply (such as what benign of executable the file is). These low-level details are beyond the scope of their discussion, but the man page has more information.

    Important Points about the file ommand

    file tries to figure out what kind a file is based on three types of test:

  • The file kind that the ls –l command returns.

  • -The presence of a magic number at the nascence of the file identifying the file type. These numbers are defined in the file /usr/share/magic in Red Hat Linux 7.1 and /usr/lib/locale/locale/LC_MESSAGES/magic (or /etc/magic) in Solaris 8. Typically, only binary files will Have magic numbers.

  • -In the case of a regular/text file, the first few bytes are tested to determine the kind of text representation and then to determine whether the file has a recognized purpose, such as C code or a Perl script.

  • file actually opens the file and changes the atime in the inode.

    Inode lists are maintained by the filesystem itself, including which ones are free for use. Inode allocation and manipulation is every transparent to both sysadmins and users.

    Inodes become significant at two times for the sysadmin: at filesystem creation time and when the filesystem runs out of free inodes. At filesystem creation time, the total number of inodes for the filesystem is allocated. Although they are not in use, space is set aside for them. You cannot add any more inodes to a filesystem after it has been created. When you race out of inodes, you must either free some up (by deleting or moving files) or migrate to another, larger filesystem.

    Without inodes, files are just a random assortment of ones and zeros on the disk. There is no guarantee that the file will live stored sequentially within a sector or track, so without an inode to point the course to the data blocks, the file is lost. In fact, every file is uniquely identified by the combination of its filesystem cognomen and inode number.

    See Appendix B for more detailed information on the exact content of inodes and their structure.

    Linux has a very useful command called stat that dumps the contents of an inode in a tidy format:

    [linux:9 ~]stat . File: "." Size: 16384 Filetype: Directory Mode: (0755/drwxr-xr-x) Uid: (19529/ robin) Gid:(20/users) Device: 0,4 Inode: 153288707 Links: 78 Access: Sun Jul 22 13:58:29 2001(00009.04:37:59) Modify: Sun Jul 22 13:58:29 2001(00009.04:37:59) Change: Sun Jul 22 13:58:29 2001(00009.04:37:59) Boot obscure and Superblock

    When a filesystem is created, two structures are automatically created, whether they are immediately used or not. The first is called the boot block, where boot-time information is stored. Because a partition may live made bootable at will, this structure needs to live available at every times.

    The other structure, of more interest here, is the superblock. Just as an inode contains meta-information about a file, a superblock contains metainformation about a filesystem. Some of the more captious contents are listed here:18

  • Filesystem name

  • Filesystem size

  • Timestamp: final update

  • Superblock status flag

  • Filesystem status flag: clean, stable, active

  • Number of free blocks

  • List of free blocks

  • Pointer to next free block

  • Size of inode list

  • Number of free inodes

  • List of free inodes

  • Pointer to next free inode

  • Lock fields for free blocks and inodes

  • Summary data block

  • And you thought inodes were complex.

    The superblock keeps track of free file blocks and free inodes so that the filesystem can store recent files. Without these lists and pointers, a long, sequential search would Have to live performed to find free space every time a file was created.

    In much the very course that files without inodes are lost, filesystems without intact superblocks are inaccessible. That's why there is a superblock status flag—to testify whether the superblock was properly and completely updated before the disk (or system) was final taken offline. If it was not, then a consistency check must live performed for the whole filesystem and the results stored back in the superblock.

    Again, more detailed information about the superblock and its role in UNIX filesystems may live create in Appendix B.

    Filesystem Types

    Both Red Hat and Solaris recognize a army of different filesystem types, although you will generally quit up using and supporting just a few. There are three measure types of filesystem—local, network, and pseudo—and a fourth "super-filesystem" kind that is actually losing ground, given the size of modern disks.

    Local Filesystems

    Local filesystems are common to every system that has its own local disk.19 Although there are many instances of this kind of filesystem, they are every designed to labor within a system, managing the components discussed in the final section and interfacing with the physical drive(s).

    Only a few local filesystems are specifically designed to live cross-platform (and sometimes even cross–OS-type). They near in handy, though, when you Have a nondisk hardware failure; you can just bewitch the disk and achieve it into another machine to retrieve the data.20 The UNIX File System, or ufs, was designed for this; both Solaris and Red Hat Linux machines can consume disks with this filesystem. Note that Solaris uses ufs filesystems by default. Red Hat's default local filesystem is ext2.

    Another local, cross-platform filesystem is ISO9660, the CD-ROM standard. This is why you can read your Solaris CD in a Red Hat box's reader.

    Local filesystems near in two related but sunder flavors. The original, measure model filesystem is silent in broad consume today. The newer journaling filesystem kind is just nascence to really near into its own. The major disagreement between the two types is the course they track changes and finish integrity checks.

    Standard Filesystems

    Standard, nonjournaling filesystems depend on flags in the superblock for consistency regulation. If the superblock flag is not set to "clean," then the filesystem knows that it was not shut down properly: not every write buffers were flushed to disk, and so on. Inconsistency in a filesystem means that allocated inodes could live overwritten; free inodes could live counted as in use—in short, rampant file corruption, mass hysteria.

    But there is a filesystem integrity checker to deliver the day: fsck. This command is usually invoked automatically at boot-time to verify that every filesystems are spotless and stable. If the / or /usr filesystems are inconsistent, the system might prompt you to start up a miniroot shell and manually race fsck. A few of the more captious items checked and corrected are listed here:

  • Unclaimed blocks and inodes (not in free list or in use)

  • Unreferenced but allocated blocks and inodes

  • Multiply claimed blocks and inodes

  • Bad inode formats

  • Bad directory formats

  • Bad free obscure or inode list formats

  • Incorrect free obscure or inode counts

  • Superblock counts and flags

  • Note that a filesystem should live unmounted before running fsck (see the later section "Administering Local Filesystems"). Running fsck on a mounted filesystem might occasions a system panic and crash, or it might simply spurn to race at all. It's too best, though not required, that you race fsck on the raw device, when possible. behold the man page for more details and options.

    So where does fsck achieve orphans, the blocks and inodes that are clearly in consume but aren't referenced anywhere? Enter the lost+found directories. There is always a /lost+found directory on every system; other directories accrue them as fsck finds orphans in their purview. fsck automatically creates the directories as needed and renames the lost blocks into there by inode number. behold the man pages "mklost+found" on Red Hat and "fsck_ufs" on Solaris.

    Journaling Filesystems

    Journaling filesystems finish away with fsck and its concomitant superblock structures. every filesystem status information is internally tracked and monitored, in much the very course that databases systems set up checkpoints and self-verifications.

    With journaling filesystems, you Have a better chance of full data recovery in the event of a system crash. Even unsaved data in buffers can live recovered thanks to the internal log.21 This benign of weakness tolerance makes journaling filesystems useful in high- availability environments.

    The drawback, of course, is that when a filesystem dote this gets corrupted somehow, it presents major difficulties for recovery. Most journaling filesystems provide their own salvaging programs for consume in case of emergency. This underscores how captious backups are, no matter what benign of filesystem software you've invested in. behold Chapter 16, "Backups," for more information.

    One of the earliest journaling filesystems is silent a commercial venture: VxFS by Veritas. Another pioneer has decided to release its software into the public domain under GPL22 licensing: JFS23 by IBM. SGI's xfs journaling filesystem has been freely available under GPL since about 1999, although it is only designed to labor under IRIX and Linux.24

    Maintenance of filesystem status incurs an overhead when using journaling filesystems. As a result, these filesystems achieve suboptimally for diminutive filesystem sizes. Generally, journaling filesystems are commandeer for filesystem sizes of 500Mb or more.

    Network Filesystems

    Network-based filesystems are really add-ons to local filesystems because the file server must Have the actual data stored in one of its own local filesystems.25 Network file- systems Have both a server and client program.

    The server usually runs as a daemon on the system that is sharing disk space. The server's local filesystems are unaffected by this extra process. In fact, the daemon generally only puts a few messages in the syslog and is otherwise only visible through ps.

    The system that wants to access the server's disk space runs the client program to mount the shared filesystems across the network. The client program handles every the I/O so that the network filesystem behaves just a dote a local filesystem toward the client machine.

    The old-fashioned standby for network-based filesystems is the Network File System (NFS). The NFS measure is currently up to revision 3, though there are quite a number of implementations with their own version numbers. Both Red Hat and Solaris near measure with NFS client and server packages. For more details on the inner workings and configuration of NFS, behold Chapter 13, "File Sharing."

    Other network-based filesystems embrace AFS (IBM's Andrew File System) and DFS/DCE (Distributed File System, allotment of the Open Group's Distributed Computing Environment). The mechanisms of these advanced filesystems go beyond the scope of this book, although their goal is silent the same: to efficiently partake files across the network transparently to the user.

    Pseudo Filesystems

    Pseudofilesystems are an bewitching progress in that they are not actually related to disk-based partitions. They are instead purely rational constructs that limn information and meta-information in a hierarchical structure. Because of this structure and because they can live manipulated with the mount command, they are silent referred to as filesystems.

    The best illustration of pseudofilesystems exists on both Red Hat and Solaris systems: /proc. Under Solaris, /proc is restricted to just managing process information:

    [sun:1 ~]ls /proc 0 145 162 195 206 230 262 265 272 286 299 303 342 370 403 408 _672 752 1 155 185 198 214 243 263 266 278 292 3 318 360 371 404 52 _674 142 157 192 2 224 252 264 268 280 298 302 319 364 400 406 58 _678

    Note that these directories are every named according to the process numbers corresponding to what you would find in the output of ps. The contents of each directory are the various meta-information that the system needs to manage the process.

    Under Red Hat, /proc provides information about processes as well as about various system components and statistics:

    [linux:1 ~] ls /proc 1 18767 23156 24484 25567 28163 4 493 674 8453 ksyms _stat 13557 18933 23157 24486 25600 3 405 5 675 9833 loadavg _swaps 13560 18934 23158 24487 25602 3050 418 5037 676 9834 locks _sys 13561 18937 23180 24512 25603 3051 427 5038 7386 9835 mdstat _tty 1647 19709 23902 24541 25771 3052 441 5054 7387 bus meminfo _uptime 1648 19730 23903 24775 25772 30709 455 5082 7388 cmdline misc _version 1649 19732 23936 25494 25773 30710 473 510 7414 cpuinfo modules 16553 19733 24118 25503 25824 30712 485 5101 7636 devices mounts 18658 2 24119 25504 25882 30729 486 524 7637 dma mtrr 18660 21450 24120 25527 25920 320 487 558 7638 filesystems net 18661 21462 24144 25533 26070 335 488 6 7662 fs _partitions 18684 21866 24274 25534 26071 337 489 670 8426 interrupts pci 18685 21869 24276 25541 26072 338 490 671 8427 ioports scsi 18686 21870 24277 25542 28161 339 491 672 8428 kcore self 18691 21954 24458 25543 28162 365 492 673 8429 kmsg slabinfo

    Again they behold the directories named for process numbers, but they too behold directories with indicative names such as cpuinfo and loadavg. Because this is a hierarchical filesystem, you can cd into these directories and read the various files for their system information.

    The most bewitching thing about /proc is that it allows even processes to live treated dote files.26 This means that pretty much everything in UNIX, whether it is something that just exists or something that actually happens, can now live considered a file.

    For more information under Red Hat, kind man proc. For more information under Solaris, kind man –s 4 proc.

    Logical Volumes

    Finally, there are the "super-filesystems" or rational volumes that finish what the other major types of filesystem cannot: surmount the barriers of partitions. You may well inquire of why anyone would want to finish that. There are two reasons. First, because disks used to live a lot smaller and more costly, you used what you had at hand. If you needed a great pool of disk space, rational volumes allowed you to aggregate remnants into something useable. Second, even with larger disks, you silent might not live able to achieve the benign of disk space required by a particular researcher or program. Once again, rational volumes allow you to aggregate partitions across disks to profile one great filesystem.

    Crossing disk boundaries with a rational volume is referred to as disk spanning. Once you Have rational volumes, you can too Have some fairly complicated data management methods and performance-enhancing techniques. Disk striping, for example, is a performance booster. Instead of sequentially filling one disk and then the next in series, it spreads the data in discrete chunks across disks, allowing better I/O response through parallel operations.

    RAID27 implements rational volumes at 10 sunder levels, with various features at each level. This implementation can live done either in hardware or in software, although the nomenclature for both is the same.28

    Table 3.4 RAID Levels

    RAID Level

    Features

    Implications

    0

    Disk striping

    Fastest

    Not self-repairing

    1

    Disk mirroring

    Fast

    Self-repairing

    -Requires extra drives for data duplication

    2

    Disk striping

    Fast

    Error correction

    Self-repairing

    (Very similar to RAID-3)

    3

    Disk striping

    Slower

    Parity disk

    Self-repairing

    Error correction

    Requires sunder parity disk

    4

    Disk striping

    Slower

    Parity disk

    Self-repairing

    Requires sunder parity disk

    (Very similar to RAID-5)

    5

    Disk striping

    Slowest for writes, but

    Rotating parity array

    good for reads

    Self-repairing

    Requires three to five sunder parity disks

    Reconstruction by parity data (not duplication)

    6

    RAID-5 + secondary

    Not in broad use

    parity scheme

    7

    RAID-5 + real-time embedded controller

    Not in broad use

    0+1

    Mirrored striping

    -RAID-0 array duplicated (mirrored)

    1+0

    Striped mirroring

    -Each stripe is RAID-1 (mirrored) array

    High cost

    0+3

    Array of parity stripes

    Each stripe is RAID-3 array

    High cost

    Clearly, the benign of complexity inherent in every rational volume systems requires some benign of back-end management system. Red Hat offers the rational Volume Manager (LVM) as a kernel module. While the details of LVM are beyond the scope of this book, it is bewitching to note that you can achieve any filesystem that you want on top of the rational volume. Start at http://www.linuxdoc.org/HOWTO/LVM-HOWTO.htmlfor more details.

    Although Sun offers rational volume management, it is through a for-pay program called "Solstice DiskSuite." The filesystem on DiskSuite rational volumes must live ufs. For more information, start at http://docs.sun.com/ab2/coll.260.2/DISKSUITEREF.

    Another commercial rational volume manager for Solaris comes from Veritas; see: http://www.veritas.com/us/products/volumemanager/faq.html#a24

    The beauty of every rational volumes is that they materialize to live just another local filesystem and are completely transparent to the user. However, rational volumes finish add some complexity for the systems administrator, and the schema should live carefully documented on paper, in case it needs to live re-created.

    NAS

    Normally, a file server's disks are directly attached to the file server. With network-attached storage (NAS), the file server and the disks that it serves are sunder entities, communicating over the local network. The storage disks require an aggregate controller that arbitrates file I/O requests from the external server(s). The server(s) and the aggregate controller each Have sunder network IP addresses. To serve the files to clients, a file (or application) server sends file I/O requests to the NAS aggregate controller and relays the results back to client systems.

    NAS is touched on here for completeness—entire books can live written about NAS design and implementation. NAS does not really limn a kind of filesystem, but rather it is a mechanism to alleviate the file server from the details of hardware disk access by isolating them in the network-attached storage unit.

    Red Hat Filesystem Reference Table

    Table 3.5 lists major filesystems that currently champion (or are supported by) Red Hat.29 The filesystem types that are currently natively supported are listed in /usr/src/linux/ fs/filesytems.c.

    Table 3.5 Filesystem Types and Purposes, with Examples (Red Hat)

    Filesystem Type

    Specific Instances (as Used in /etc/fstab)

    Purpose

    Local

    ext2

    Red Hat default filesystem

    ufs

    Solaris compatibility

    jfs

    Journaling filesystem from IBM

    xfs

    Journaling filesystem from SGI

    msdos

    Windows compatibility: DOS

    ntfs

    Windows compatibility: NT

    vfat

    Windows compatibility: FAT-32

    sysv

    SYS-V compatibility

    iso9660

    CD-ROM

    Adfs hfs romfs

    Others

    Affs hpfs smbfs

    Coda mnix udf

    devpts ncpfs umsdos

    efs qux4

    coherent

    Deprecated, pre-kernel 2.1.21

    ext

    xenix

    xiafs

    Network

    afs

    Network-based remote communication

    autofs

    nfs

    Pseudo

    proc

    Store process (and other system) meta-information

    Solaris Filesystem Reference Table

    Table 3.6 lists major filesystems that currently champion (or are supported by) Solaris. The filesystem types that currently are natively supported are listed as directories under /usr/lib/fs.

    Table 3.6 Filesystem Types and Purposes, with Examples (Solaris)

    Filesystem Type

    Specific Instances (as Used in /etc/vfstab)

    Purpose

    Local

    ufs

    Solaris default filesystem; Red Hat-compatible

    pcfs

    PC filesystem

    hsfs

    CD-ROM

    jfs

    Journaling filesystem from IBM

    Network

    afs

    Network-based remote communication

    nfs

    Pseudo

    procfs

    Store process metainformation

    Fdfs swapfs tmpfs

    Mount metainformation areas as filesystems

    mntfs cachefs lofs

    fifofs specfs udfs namefs



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    ASQ [3 Certification Exam(s) ]
    ASTQB [8 Certification Exam(s) ]
    Autodesk [2 Certification Exam(s) ]
    Avaya [96 Certification Exam(s) ]
    AXELOS [1 Certification Exam(s) ]
    Axis [1 Certification Exam(s) ]
    Banking [1 Certification Exam(s) ]
    BEA [5 Certification Exam(s) ]
    BICSI [2 Certification Exam(s) ]
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    CIDQ [1 Certification Exam(s) ]
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    ECDL [1 Certification Exam(s) ]
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    Ericsson [5 Certification Exam(s) ]
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    F5-Networks [20 Certification Exam(s) ]
    FCTC [2 Certification Exam(s) ]
    Filemaker [9 Certification Exam(s) ]
    Financial [36 Certification Exam(s) ]
    Food [4 Certification Exam(s) ]
    Fortinet [12 Certification Exam(s) ]
    Foundry [6 Certification Exam(s) ]
    FSMTB [1 Certification Exam(s) ]
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    Genesys [4 Certification Exam(s) ]
    GIAC [15 Certification Exam(s) ]
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    GuidanceSoftware [2 Certification Exam(s) ]
    H3C [1 Certification Exam(s) ]
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    Healthcare [3 Certification Exam(s) ]
    HIPAA [2 Certification Exam(s) ]
    Hitachi [30 Certification Exam(s) ]
    Hortonworks [4 Certification Exam(s) ]
    Hospitality [2 Certification Exam(s) ]
    HP [746 Certification Exam(s) ]
    HR [4 Certification Exam(s) ]
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    Hyperion [10 Certification Exam(s) ]
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    IBM [1530 Certification Exam(s) ]
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    Intel [2 Certification Exam(s) ]
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    IRS [1 Certification Exam(s) ]
    ISA [1 Certification Exam(s) ]
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    ISC2 [6 Certification Exam(s) ]
    ISEB [24 Certification Exam(s) ]
    Isilon [4 Certification Exam(s) ]
    ISM [6 Certification Exam(s) ]
    iSQI [7 Certification Exam(s) ]
    ITEC [1 Certification Exam(s) ]
    Juniper [63 Certification Exam(s) ]
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    LPI [24 Certification Exam(s) ]
    LSI [3 Certification Exam(s) ]
    Magento [3 Certification Exam(s) ]
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    McAfee [8 Certification Exam(s) ]
    McData [3 Certification Exam(s) ]
    Medical [69 Certification Exam(s) ]
    Microsoft [368 Certification Exam(s) ]
    Mile2 [2 Certification Exam(s) ]
    Military [1 Certification Exam(s) ]
    Misc [1 Certification Exam(s) ]
    Motorola [7 Certification Exam(s) ]
    mySQL [4 Certification Exam(s) ]
    NBSTSA [1 Certification Exam(s) ]
    NCEES [2 Certification Exam(s) ]
    NCIDQ [1 Certification Exam(s) ]
    NCLEX [2 Certification Exam(s) ]
    Network-General [12 Certification Exam(s) ]
    NetworkAppliance [36 Certification Exam(s) ]
    NI [1 Certification Exam(s) ]
    NIELIT [1 Certification Exam(s) ]
    Nokia [6 Certification Exam(s) ]
    Nortel [130 Certification Exam(s) ]
    Novell [37 Certification Exam(s) ]
    OMG [10 Certification Exam(s) ]
    Oracle [269 Certification Exam(s) ]
    P&C [2 Certification Exam(s) ]
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    PayPal [1 Certification Exam(s) ]
    Pegasystems [11 Certification Exam(s) ]
    PEOPLECERT [4 Certification Exam(s) ]
    PMI [15 Certification Exam(s) ]
    Polycom [2 Certification Exam(s) ]
    PostgreSQL-CE [1 Certification Exam(s) ]
    Prince2 [6 Certification Exam(s) ]
    PRMIA [1 Certification Exam(s) ]
    PsychCorp [1 Certification Exam(s) ]
    PTCB [2 Certification Exam(s) ]
    QAI [1 Certification Exam(s) ]
    QlikView [1 Certification Exam(s) ]
    Quality-Assurance [7 Certification Exam(s) ]
    RACC [1 Certification Exam(s) ]
    Real-Estate [1 Certification Exam(s) ]
    RedHat [8 Certification Exam(s) ]
    RES [5 Certification Exam(s) ]
    Riverbed [8 Certification Exam(s) ]
    RSA [15 Certification Exam(s) ]
    Sair [8 Certification Exam(s) ]
    Salesforce [5 Certification Exam(s) ]
    SANS [1 Certification Exam(s) ]
    SAP [98 Certification Exam(s) ]
    SASInstitute [15 Certification Exam(s) ]
    SAT [1 Certification Exam(s) ]
    SCO [10 Certification Exam(s) ]
    SCP [6 Certification Exam(s) ]
    SDI [3 Certification Exam(s) ]
    See-Beyond [1 Certification Exam(s) ]
    Siemens [1 Certification Exam(s) ]
    Snia [7 Certification Exam(s) ]
    SOA [15 Certification Exam(s) ]
    Social-Work-Board [4 Certification Exam(s) ]
    SpringSource [1 Certification Exam(s) ]
    SUN [63 Certification Exam(s) ]
    SUSE [1 Certification Exam(s) ]
    Sybase [17 Certification Exam(s) ]
    Symantec [134 Certification Exam(s) ]
    Teacher-Certification [4 Certification Exam(s) ]
    The-Open-Group [8 Certification Exam(s) ]
    TIA [3 Certification Exam(s) ]
    Tibco [18 Certification Exam(s) ]
    Trainers [3 Certification Exam(s) ]
    Trend [1 Certification Exam(s) ]
    TruSecure [1 Certification Exam(s) ]
    USMLE [1 Certification Exam(s) ]
    VCE [6 Certification Exam(s) ]
    Veeam [2 Certification Exam(s) ]
    Veritas [33 Certification Exam(s) ]
    Vmware [58 Certification Exam(s) ]
    Wonderlic [2 Certification Exam(s) ]
    Worldatwork [2 Certification Exam(s) ]
    XML-Master [3 Certification Exam(s) ]
    Zend [6 Certification Exam(s) ]





    References :


    zoho.com : https://docs.zoho.com/file/67jzbaa0e919da2d942758d3f5122e10e7896
    Box.net : https://app.box.com/s/zsmhzb4qqcbtcnu1f3he9eh76soo5tk4






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