Veritas NetBackup Snapshot Client Administrator's Guide

Last Published:
Product(s): NetBackup (8.1.1)
Platform: Linux,UNIX,Windows
  1. Introduction
    1.  
      Snapshot Client features at a glance
    2. Snapshot Client features
      1.  
        About snapshots
      2.  
        About snapshot methods
      3.  
        About snapshot providers
      4.  
        About off-host backup support
      5.  
        About Instant Recovery
      6.  
        About FlashBackup policies
      7.  
        About snapshot methods for disk arrays
      8.  
        About block level incremental backup
      9.  
        About Snapshot Client and NDMP
    3. About snapshot basics
      1.  
        About the copy-on-write snapshot type
      2.  
        About the mirror snapshot type
    4.  
      Benefits of copy-on-write versus mirror
    5.  
      About local backup of a snapshot
    6. Off-host backup overview
      1.  
        About file and volume mapping methods
    7. Off-host backup methods
      1. About alternate client backup
        1.  
          About data sharing between clients
        2.  
          Alternate client backup split mirror examples
        3.  
          Alternate client backup through data replication example (UNIX only)
      2.  
        FlashBackup and alternate client combination example
      3.  
        NetBackup media server data mover example (UNIX only)
      4.  
        About the NDMP data mover
    8. Snapshot Client requirements
      1.  
        Snapshot Client restrictions
    9.  
      Snapshot Client terminology
    10.  
      Snapshot Client assistance
    11.  
      About open file backups for Windows
  2. Installation
    1.  
      Installation prerequisites for Snapshot Client
    2.  
      Snapshot Client installation notes
    3.  
      About distributing Client Software in mixed-platform environments
    4.  
      About creating log directories
    5.  
      About the snapshot state file
  3. Policy configuration
    1.  
      Notes on Snapshot Client policies
    2.  
      Configuring a Snapshot Client policy
    3.  
      Backup Selections tab options when configuring a policy
    4.  
      Off-host backup configuration options
    5.  
      Automatic snapshot selection
    6. Selecting the snapshot method
      1.  
        Snapshot methods
      2. Configuration parameters for Snapshot Client
        1.  
          Cache device path parameter
        2.  
          Delay in seconds between disk group split retries parameter
        3.  
          IBC receive timeout parameter (seconds)
        4.  
          IBC send timeout parameter (seconds)
        5.  
          Keep snapshot after backup parameter
        6.  
          Maximum number of volumes to resynchronize concurrently parameter
        7.  
          Maximum Snapshots parameter (Instant Recovery only)
        8.  
          Number of times to retry disk group split parameter
        9.  
          Provider Type parameter
        10.  
          Resynchronize mirror in background parameter
        11.  
          Snapshot Attribute parameter
        12.  
          Sync I/O delay in milliseconds parameter (UNIX only)
        13.  
          Sync region size in MB parameter (UNIX only)
        14.  
          Wait for mirror sync completion parameter
        15.  
          Important note on VSS and disk arrays
        16.  
          Synchronize mirror before the backup parameter
      3.  
        Snapshot Resources
    7.  
      Configuring backup scripts
    8. About using alternate client backup
      1.  
        Alternate client backup requirements
    9. Configuring alternate client backup
      1.  
        Before running the alternate client backup
      2.  
        Example alternate client backup configurations
    10. Policy configuration tips
      1.  
        Maximum pathname length
      2.  
        Snapshot tips
      3.  
        Multiple data streams
      4. About incremental backup of mirror-based snapshots
        1.  
          Incremental backup options (Windows only)
        2.  
          Snapshot sequence and access time
    11. About disabling snapshots
      1.  
        Disabling Open File Backups on Windows
      2.  
        Disabling Snapshot Client snapshots
  4. FlashBackup configuration
    1.  
      About FlashBackup
    2. FlashBackup restrictions
      1.  
        Restores of Windows encrypted files and hard links
    3.  
      Configuring a FlashBackup policy
    4. Configuring FlashBackup policy for backward compatibility (UNIX only)
      1.  
        About the cache partition
      2.  
        Requirements for the cache partition
      3.  
        Directives for multiple data streams
  5. Instant Recovery configuration
    1.  
      About Instant Recovery capabilities
    2.  
      Instant Recovery requirements
    3.  
      Instant Recovery restrictions
    4.  
      Giving full server privileges to the media server
    5. About Instant Recovery
      1.  
        About snapshot and backup for Instant Recovery
      2.  
        About NetBackup catalog maintenance
      3. About snapshot management
        1.  
          About snapshot rotation
      4. Means of controlling snapshots
        1.  
          Snapshot Resources pane
        2.  
          Maximum Snapshots parameter
    6.  
      Configuring a policy for Instant Recovery
    7. About sizing the cache for Instant Recovery copy-on-write snapshots
      1.  
        Cache size during restore
      2.  
        Setting an adequate size for the snapshot cache
      3.  
        Large restores from an Instant Recovery snapshot
    8. About configuring VxVM
      1.  
        Creating a snapshot mirror
      2. About creating Instant Snapshots
        1.  
          Creating space-optimized snapshots
        2.  
          Creating full-sized snapshots
      3.  
        Using the VxVM 3.5 GUI to configure VxVM mirrors
    9.  
      Modifying the VxVM or FlashSnap resync options for point in time rollback
    10.  
      Instant Recovery for databases
    11. About storage lifecycle policies for snapshots
      1.  
        Configuring a storage lifecycle policy to manage snapshot-based backups for Instant Recovery
      2.  
        Storage lifecycle polices and Snapshot Client troubleshooting
  6. Network Attached Storage (NAS) snapshot configuration
    1.  
      About NAS snapshot overview
    2.  
      Notes on NAS_Snapshot
    3.  
      Logging on to the NetBackup Client Service as the Administrator
    4.  
      Setting up a policy for NAS snapshots
    5.  
      NAS snapshot naming scheme
  7. Configuration of software-based snapshot methods
    1. Software-based snapshot methods
      1.  
        About nbu_snap
      2. Cache device requirements
        1.  
          Determining a size for the cache partition
        2.  
          Entering the cache
      3. About VxFS_Checkpoint
        1.  
          VxFS multi-volume system
        2.  
          Storage Checkpoint disk usage
        3.  
          Checkpoint retention schedules
        4.  
          Block-Level restore
      4.  
        About VxFS_Snapshot
      5. About VxVM
        1.  
          Creating a snapshot mirror of the source
        2.  
          About VxVM instant snapshots
        3.  
          About NetBackup snapshot methods
        4.  
          Space-Optimized instant snapshots
      6. About FlashSnap
        1.  
          Testing volumes for FlashSnap
      7. About VVR
        1.  
          VVR volume replication configuration
        2.  
          VVR name registration
        3.  
          Primary and secondary disk group and volume names for VVR
        4.  
          Testing the replication setup with VVR
      8.  
        About NAS_Snapshot
      9. About VSS
        1.  
          Disk array reconfiguration steps
        2.  
          Configuration and testing of volumes with VSS
        3.  
          Notes and restrictions on VSS
  8. Support for Cluster Volume Manager Environments (CVM)
    1.  
      About support for CVM environments
    2.  
      Note on NetBackup and CVM
    3.  
      About enabling VxVM or FlashSnap snapshots in a CVM environment
    4.  
      About enabling the NetBackup client to execute VxVM commands on the CVM master node
  9. Configuration of snapshot methods for disk arrays
    1. About the new disk array snapshot methods
      1.  
        About array-specific methods vs array-independent methods
      2.  
        Advantages of the new array-specific methods
      3.  
        About types of disk array methods
      4.  
        Important disk array method notes and restrictions
      5.  
        Disk array methods at a glance
    2. Disk array configuration tasks
      1.  
        Configuration tasks for the array administrator
      2.  
        Configuration tasks for the NetBackup administrator
      3.  
        Disk array configuration tasks diagram
    3. OS-specific configuration tasks
      1.  
        About dynamic multi-pathing
      2. HBA configuration
        1.  
          HBA persistent target bindings
      3. About Solaris sd.conf file
        1.  
          Solaris sd.conf file (Hitachi arrays only)
      4.  
        Linux modprobe.conf file
      5.  
        Verifying NetBackup client access, zoning, and LUN masking
    4. About VSS configuration (Windows)
      1.  
        Note on NetBackup array credentials
      2. Initial configuration of certain arrays
        1.  
          Creating EMC disk groups for VSS differential snapshots that use EMC TimeFinder Snap
        2.  
          Verifying that VSS can make a snapshot
        3.  
          Testing the EMC TimeFinder Snap backup
    5. About EMC CLARiiON arrays
      1.  
        EMC CLARiiON software requirements for UNIX
      2.  
        Veritas support for VSS Snapshot and EMC CLARiiON
      3.  
        Diagram of installed software for EMC CLARiiON
      4.  
        Verifying connectivity from client to array
      5.  
        About resolving host names on the network
      6. Configuring NetBackup to access the CLARiiON array
        1.  
          About using a local scope CLARiiON administrator account
      7.  
        Adding clients to a CLARiiON storage group
      8.  
        Configuring for EMC_CLARiiON_SnapView_Clone
      9.  
        Creating a clone private LUN with the EMC Navisphere Web interface
      10.  
        Creating a clone group and select a LUN as source
      11.  
        Adding clone LUNs to the clone group
      12.  
        Obtaining the device identifier for each source and clone LUN
      13.  
        About configuration for EMC_CLARiiON_SnapView_Snapshot
      14.  
        Configuring a reserved LUN pool for the storage processors
      15. Configuring a NetBackup policy for a CLARiiON array method
        1.  
          Configuring a policy using EMC_CLARiiON_Snapview_Clone method
        2.  
          Configuring the EMC_CLARiiON_Snapview_Clone method
        3.  
          EMC_CLARiiON_Snapview_Snapshot method
      16.  
        Common CLARiiON array configuration problems
    6. About EMC Symmetrix arrays
      1.  
        EMC Symmetrix DMX software requirements
      2.  
        Clone emulation flag can cause snapshots to fail
      3.  
        EMC snapshot operation fails
      4.  
        Support for EMC Symmetrix with Volume Shadow Copy Service
      5.  
        Prerequisites for using EMC Symmetrix disk arrays
      6.  
        Configuring NetBackup clients to use EMC Symmetrix
      7.  
        About configuring NetBackup to access the Symmetrix array
      8. About configuration for EMC_TimeFinder_Mirror
        1.  
          Fully synchronizing STD/BCV mirror pairs
      9. About configuration for EMC_TimeFinder_Clone
        1.  
          Verifying that the clone is complete before doing a point in time rollback
      10.  
        About configuration for EMC_TimeFinder_Snap
      11.  
        Configuring a policy for EMC_TimeFinder methods
    7. About HP EVA arrays
      1.  
        Prerequisites for working with HP EVA arrays
      2.  
        HP EVA software requirements for UNIX
      3.  
        Diagram of installed software for HP EVA
      4.  
        Veritas support for VSS Snapshot and HP EVA
      5. Verifying connectivity from clients to array using SSSU 5.0
        1.  
          Troubleshooting the SSSU procedure
        2.  
          Policy validation failure for the SSSU command
      6.  
        Configuring NetBackup to access the EVA array
      7.  
        Configuring a NetBackup policy for an HP EVA array method
      8.  
        HP EVA restrictions
    8. About IBM DS6000 and DS8000 arrays
      1.  
        IBM DS6000 and DS8000 software requirements
      2.  
        Preconfiguration for IBM arrays
      3. Configuring NetBackup to access the IBM DS6000 or DS8000 array
        1.  
          Configuring array access for NetBackup hosts not named in a policy
      4.  
        Configuring the IBM array for NetBackup
      5.  
        Using DSCLI commands to obtain unique IBM identifiers
      6.  
        Configuring a NetBackup policy for IBM_DiskStorage_FlashCopy
      7.  
        For further reference on IBM arrays
    9. About IBM DS4000 array
      1.  
        Array preconfiguration tasks
      2.  
        IBM 4000 software requirements
      3.  
        Verifying NetBackup client access, zoning, and LUN masking
      4.  
        Configuring NetBackup to access the IBM DS4000 array
      5.  
        Configuring the IBM 4000 array for NetBackup
      6.  
        Configuring a NetBackup policy for IBM_StorageManager_FlashCopy
    10. About Hitachi SMS/WMS/AMS, USP/NSC, USP-V/VM
      1. Hitachi array software requirements
        1.  
          Determining the current RAID Manager version
      2.  
        Preconfiguration for Hitachi
      3.  
        About communication between NetBackup and the Hitachi array
      4.  
        Determining if the Hitachi command devices are visible
      5.  
        About configuring the Hitachi array for NetBackup
      6.  
        Obtaining the Hitachi array serial number and the unique device identifiers
      7.  
        Configuring a NetBackup policy for Hitachi_ShadowImage or Hitachi_CopyOnWrite
    11. About HP-XP arrays
      1.  
        HP-XP array software requirements
      2.  
        Preconfiguration for HP-XP
      3.  
        About communication between NetBackup and the HP-XP array
      4.  
        Determining if the HP-XP command devices are visible
      5.  
        About configuring the HP-XP array for NetBackup
      6.  
        Obtaining the array serial number and unique HP-XP identifiers
      7.  
        Configuring a NetBackup policy for HP_XP_BusinessCopy and HP_XP_Snapshot
    12. About array troubleshooting
      1. Troubleshooting issues pertaining to all arrays
        1.  
          Troubleshooting Solaris issues
        2.  
          Troubleshooting host OS type specification
      2.  
        Troubleshooting NetBackup and EMC CLARiiON arrays
      3.  
        Troubleshooting NetBackup and EMC Symmetrix arrays
      4.  
        Troubleshooting NetBackup and HP EVA arrays
      5. Troubleshooting IBM DS6000 and DS8000 arrays
        1.  
          Snapshot errors with IBM DS6000 and DS8000 arrays (NetBackup status code 156)
      6. Troubleshooting IBM4000 arrays
        1.  
          Snapshot errors encountered with IBM4000 arrays (NetBackup status code 156)
        2.  
          For further reference on IBM System Storage DS4000
      7. Troubleshooting Hitachi arrays
        1.  
          NetBackup policy validation fails with Hitachi arrays
        2.  
          Backup or restore or image expiration fails with Hitachi arrays
  10. Notes on Media Server and Third-Party Copy methods
    1.  
      Disk requirements for Media Server and Third-Party Copy methods
    2.  
      Directives for Media Server and Third-Party Copy methods
    3.  
      Storage units for Media Server and Third-Party Copy methods
    4.  
      Preventing multiplexing on a third-party copy backup
    5.  
      Raw partition backups
    6.  
      Increasing the client read timeout for all clients
    7.  
      Further information on off-host data mover backups
  11. Backup and restore procedures
    1.  
      About performing a backup
    2.  
      About performing a restore
    3. About restores from a FlashBackup backup
      1.  
        Notes for FlashBackup and UNIX client restore
      2.  
        Notes for FlashBackup and Windows client restore
    4.  
      Restoring a large number of files in a clustered file system (VxFS on UNIX Only)
    5. Instant Recovery restore features
      1. About Instant Recovery: block-level restore
        1.  
          Activating and deactivating block-level restore
      2. About Instant Recovery: file promotion
        1.  
          Notes on file promotion
        2.  
          About file promotion
      3. About Instant Recovery: Fast File Resync (Windows clients only)
        1.  
          Notes on Fast File Resync (FFR)
        2.  
          Notes on Fast File Resync (FFR) and the files to be restored
        3.  
          About using Fast File Resync
        4.  
          When NetBackup uses Fast File Resync
      4. About Instant Recovery: point in time rollback
        1.  
          Notes on rollback
        2.  
          Performing snapshot rollback
    6.  
      Notes for restoring individual files from an Instant Recovery snapshot
    7. About configurations for restore
      1.  
        About restoring over the LAN
      2.  
        About restoring over the SAN to a host acting as both client server and media server
      3.  
        About restoring directly from a snapshot
    8. About restoring from a disk snapshot
      1. About restoring on UNIX
        1.  
          Restoring individual files on UNIX
        2.  
          Restoring the entire snapshot on UNIX
      2. About restoring on Windows
        1.  
          Restoring individual files on Windows
        2.  
          Restoring the entire snapshot on Windows
  12. Troubleshooting
    1.  
      About gathering information and checking logs
    2. Logging directories for UNIX platforms
      1.  
        UNIX logging directories for backup
      2.  
        UNIX logging directories for restore
      3.  
        snapctl driver messages
    3. Logging folders for Windows platforms
      1.  
        Windows logging folders for backup
      2.  
        Windows logging folders for restore
      3.  
    4.  
      Customer support contact information
    5.  
      Latest patches and updates
    6.  
      Snapshot provider information
    7.  
      Important notes on Snapshot Client
    8.  
      Snapshot Client installation problems
    9. FlashBackup and status code 13
      1.  
        The FlashBackup cache partition may have run out of space
      2.  
        Removing stale snapshots (Solaris)
    10.  
      Single file restore from a FlashBackup Instant Recovery snapshot of a file protected by Windows VSS writer fails
    11.  
      Identifying and removing a left-over snapshot
    12.  
      Removing a VxVM volume clone
    13.  
      Alternate client restore and backup from a snapshot fails
    14.  
      Restore from a snapshot fails with status 2800
    15.  
      Raw Partition restore fails with the message 'FlashBackup-Windows policy restore error'
    16.  
      Snapshot creation fails with error 156
    17.  
      Snapshot fails with error 20
    18.  
      Snapshot job fails and the snapshot command does not recognize the volume name
    19.  
      Snapshot creation fails with error 4220
    20.  
      Snapshot creation fails when the same volume is mounted on multiple mount points of the same host
    21.  
      Snapshot-based backup and restore failure
    22.  
      Multiple snapshot jobs fail with code 156 or 1541.
    23.  
      FlashBackup policy fails, with multiple backup selections [Cache =]
    24.  
      Partial backup failure with 'Snapshot encountered error 156'
    25.  
      Backup of file system validation fails with error 223
    26.  
      Policy validation fails if the specified CIFS share path contains a forward slash
    27.  
      An NDMP snapshot policy for wildcard backup fails with error 4201
    28.  
      Troubleshooting with bpfis log
    29.  
      Limitations of using HP-UX 11.31
  13. Appendix A. Managing nbu_snap (Solaris)
    1. About managing nbu_snap
      1.  
        Cache for nbu_snap
      2.  
        About determining cache size
      3.  
        About terminating nbu_snap
      4. nbu_snap commands
        1.  
          snapon command
        2.  
          snaplist command
        3.  
          snapcachelist command
        4.  
          snapstat command
        5.  
          snapoff command
  14. Appendix B. Overview of snapshot operations
    1.  
      Introduction to snapshot operations
    2.  
      Pre and post snapshot creation operations
    3.  
      About quiescing the system
    4.  
      About quiescing the database application
    5.  
      About quiescing the stack
    6.  
      File system quiesce
    7.  
      Volume manager data caching
    8.  
      How copy-on-write works
  15. Appendix C. NetBackup integration with CloudPoint for snapshot managment
    1.  
      About NetBackup and CloudPoint integration for snapshot management
    2.  
      About configuring Snapshot Management server in NetBackup
    3.  
      Configuring a CloudPoint server in NetBackup
    4.  
      Configuring CloudPoint plug-ins in NetBackup
    5.  
      Troubleshooting Cloudpoint and NetBackup integration issues

Snapshot Client terminology

Table: Snapshot Client terminology describes the terms that are used with NetBackup Snapshot Client. For explanations of other NetBackup terms, consult the NetBackup online glossary.

Table: Snapshot Client terminology

Term

Definition

Alternate client backup

The alternate client performs a backup on behalf of another client.

Backup agent (see also Third-Party Copy Device)

A general term for the host that manages the backup on behalf of the NetBackup client. The agent is either another client, the NetBackup media server, a third-party copy device, or a NAS filer.

BCV

The mirror disk in an EMC primary-mirror array configuration (see mirror). BCV stands for Business Continuance Volume.

Bridge

In a SAN network, a bridge connects SCSI devices to Fibre Channel. A third-party copy device can be implemented as part of a bridge or as part of other devices. Note that not all bridges function as third-party copy devices.

Cache

Copy-on-write snapshot methods need a separate working area on disk during the lifetime of the snapshot. This area is called a cache. The snapshot method uses the cache to store a copy of the client's data blocks that are about to change because of file system activity. This cache must be a raw disk partition that does not contain valuable information: when you use the cache, the snapshot method overwrites any data currently stored there.

See How copy-on-write works.

Copy Manager

See Third-Party Copy Device.

Copy-on-write

In NetBackup Snapshot Client, one of two types of supported snapshots (see also mirror). Unlike a mirror, a copy-on-write does not create a separate copy of the client's data. It creates a block-by-block "account" from the instant the copy-on-write was activated. The account describes which blocks in the client data have changed and which have not. The backup application uses this account to create the backup copy. Other terms and trade names sometimes used for copy-on-write snapshots are space-optimized snapshots, space-efficient snapshots, and checkpoints.

Data movement

A copy operation as performed by a third-party copy device or NetBackup media server.

Data mover

The host or entity that manages the backup on behalf of the NetBackup client. The data mover can be either the NetBackup media server, a third-party copy device, or a NAS filer.

device

A general term for any of the following: LUN, logical volume, vdisk, and BCV or STD.

Disk group

A configuration of disks to create a primary-mirror association, using commands unique to the disks' vendor. See mirror and volume group.

Extent

A contiguous set of disk blocks that are allocated for a file and represented by three values:

  • Device identifier

  • Starting block address (offset in the device)

  • Length (number of contiguous blocks)

The mapping methods in Snapshot Client determine the list of extents and send the list to the backup agent.

FastResync (VxVM)

Formerly known as Fast Mirror Resynchronization or FMR, VxVM FastResync performs quick and efficient resynchronization of mirrors. NetBackup's Instant Recovery feature uses FastResync to create and maintain a point-in-time copy of a production volume.

Fibre Channel

A type of high-speed network that is composed of either optical or of copper cable and employing the Fibre Channel protocol. NetBackup Snapshot Client supports both arbitrated loop and switched fabric (switched Fibre Channel) environments.

File system

Has two meanings. For a product, such as UFS (Sun Solaris) or VxFS (Veritas) file systems, file system means the management and the allocation schemes of the file tree. Regarding a file tree component, file system means a directory that is attached to the UNIX file tree by means of the mount command. When a file system is selected as an entry in the NetBackup Backup Selections list, this definition applies.

Instant Recovery

A restore feature of a disk snapshot of a client file system or volume. Client data can be rapidly restored from the snapshot, even after a system restart.

Mapping

Converting a file or raw device (in the file system or Volume Manager) to physical addresses or extents for backup agents on the network. NetBackup Snapshot Client uses the VxMS library to perform file mapping.

Mapping methods

A set of routines for converting logical file addresses to physical disk addresses or extents. NetBackup Snapshot Client includes support for file-mapping and volume-mapping methods.

Mirror

Has two meanings.

  • A disk that maintains an exact copy or duplicate of another disk. A mirror disk is often called a secondary, and the source disk is called the primary. All writes to the primary disk are also made to the mirror disk.

  • A type of snapshot that is captured on a mirror disk. At an appropriate moment, all further writes to the primary disk are held back from the mirror, which "splits" the mirror from the primary. As a result of the split, the mirror becomes a snapshot of the primary. The snapshot can then be backed up.

NetBackup media server method

An off-host backup method in which the NetBackup media server performs the data movement.

Off-host backup

The off-loading of backup processing to a separate backup agent executing on another host. NetBackup Snapshot Client provides the following off-host backup options: Alternate Client, NetBackup media server, Third-Party Copy Device, and Network Attached Storage.

Primary disk

In a primary-mirror configuration, client applications read and write their data on the primary disk. An exact duplicate of the primary disk is the mirror.

Raw partition

A single section of a raw physical disk device occupying a range of disk sectors. The raw partition does not have a file system or other hierarchical organization scheme (thus, a "raw" stream of disk sectors). On some operating systems, such as Solaris and HP-UX, a raw partition is different from a block device over which the file system is mounted.

Recovery Manager (RMAN)

Oracle's backup and recovery program. RMAN performs backup and restore by making requests to a NetBackup shared library.

RMAN Proxy Copy

An extension to the Oracle8i media management API which enables media management software such as NetBackup to perform data transfer directly.

SAN (storage area network)

A Fibre Channel-based network connecting servers and storage devices. The storage devices are not attached to servers but to the network itself, and are visible to all servers on the network.

Secondary disk

See mirror.

Snapshot

A point-in-time, read-only, disk-based copy of a client volume. A snapshot is created with minimal effect on other applications. NetBackup provides several types, depending on the device where the snapshot occurs: copy-on-write, mirror, clone, and snap.

Snapshot method

A set of routines for creating a snapshot. You can select the method, or let NetBackup select it when the backup is started (auto method).

Snapshot mirror

A disk mirror created by the Veritas Volume Manager (VxVM). Snapshot mirror is an exact copy of a primary volume at a particular moment, reproduced on a physically separate device.

Snapshot source

The entity (file system, raw partition, or logical volume) to which a snapshot method is applied. NetBackup automatically selects the snapshot source according to the entries in the policy's Backup Selections list.

Snapshot volume

A mirror that has been split from the primary volume or device and made available to users. Veritas Volume Manager (VxVM) creates snapshot volumes as a point-in-time copy of the primary volume. Subsequent changes in the primary volume are recorded in the Data Change Log. The recorded changes can be used to resynchronize with the primary volume by means of VxVM FastResync. The changes that were made while the snapshot volume was split are applied to the snapshot volume to make it identical to the primary volume.

Standard device

Refers to the primary disk in an EMC primary-mirror disk array (see primary disk).

Storage Checkpoint (VxFS)

Provides a consistent and a stable view of a file system image and keeps track of modified data blocks since the last checkpoint. Unlike a mirror, a VxFS Storage Checkpoint does not create a separate copy of the primary or the original data. It creates a block-by-block account that describes which blocks in the original data have changed from the instant the checkpoint was activated.

A Storage Checkpoint stores its information in available space on the primary file system, not on a separate or a designated device. (Also, the ls command does not list Storage Checkpoint disk usage; you must use the fsckptadm list command instead.)

Third-Party Copy Device

Has two meanings:

  • A backup agent on the SAN that operates on behalf of backup applications. The third-party copy device receives backup data from a disk that is attached to Fibre Channel and sends it to a storage device. The third-party copy device uses the SCSI Extended Copy command. The third-party copy device is sometimes called a Copy Manager, third-party copy engine, or data mover. In SAN hardware configurations, a third-party copy device can be implemented as part of a bridge, router, or storage device. The third-party copy device may or may not be the device to which the storage units are connected.

  • An off-host backup method in NetBackup Snapshot Client that allows backups to be made by means of a backup agent on the SAN.

UFS file system

The UNIX file system (UFS), which is the default file system type on Sun Solaris. The UFS file system was formerly the Berkeley Fast File System.

VxMS (Veritas Federated Mapping Services)

A library of routines (methods) used by NetBackup Snapshot Client to obtain the physical addresses of logical disk objects such as files and volumes.

Volume

A virtual device that is configured over raw physical disk devices (not to be confused with a NetBackup Media and Device Management volume). Consists of a block and a character device. If a snapshot source exists over a volume, NetBackup automatically uses a volume mapping method to map the volume to physical device addresses.

Volume group

A logical grouping of disks, created with the Veritas Volume Manager, to allow more efficient use of disk space.

VxFS

The Veritas extent-based File System (VxFS), designed for high performance and large volumes of data.

VxVM

The Veritas Volume Manager (VxVM), which provides the logical volume management that can also be used in SAN environments.