Snapshotroot

Use the snapshotroot option with the incremental, selective, or archive commands with an independent software vendor application that provides a snapshot of a logical volume, to associate the data on the local snapshot with the real file space data that is stored on the Tivoli® Storage Manager server.

AIX operating systems HP-UX operating systems Linux operating systems Oracle Solaris operating systems The snapshotroot option can be used to back up NFS mounted file systems. Both the backup specification (source) and the snapshotroot value can be an NFS mounted file specification. For example, the snapshotroot option can be used to backup an NFS file system that is hosted on a network-attached storage (NAS) that supports snapshot.

AIX operating systems HP-UX operating systems Linux operating systems Oracle Solaris operating systems Windows operating systems This option should be used with an incremental backup of a NAS file server volume instead of a simple incremental or incremental with snapshotroot option whenever the NAS file server is running ONTAP V7.3 for performance reasons. The snapdiff and snapshotroot options should not be used together.

Windows operating systems The snapshotroot option can be used to back up network share mounted file systems. Both the backup specification (source) and the snapshotroot value can be a network share mounted file specification. For example, the snapshotroot option can be used to back up a network share file system hosted on a network-attached storage (NAS) that supports snapshot.

AIX operating systems HP-UX operating systems Linux operating systems Oracle Solaris operating systems In the following example, filesystem test495 is NFS-mounted from a NAS file server philo and /philo/test945/.snapshot/backupsnap represents the snapshot that is created at the NAS file server.

Windows operating systems In the following example, c:\snapshots\snapshot.0 is network share that is mounted from a NAS file server and \\florance\c$ represents the snapshot that is created at the NAS file server.

  dsmc incr \\florance\C$ -snapshotroot=c:\shapshots
     \snapshot.0

AIX operating systems HP-UX operating systems Linux operating systems Oracle Solaris operating systems Windows operating systems You can also specify a directory with the snapshotroot option when you backup each file set as a separate file space.

The snapshotroot option does not provide any facilities to take a volume snapshot, only to manage data that is created by a volume snapshot.

For example, consider an application that takes a snapshot of the /usr file system and mounts it as /snapshot/day1. If you back up this data by using the following command, a unique file space that is called /snapshot/day1 is created on the server.

   dsmc incremental /snapshot/day1

However, you might want to associate the snapshot data with the data already processed for the /usr file system. Using the snapshotroot option, you can associate the data with the file space corresponding to the /usr file system on the Tivoli Storage Manager server:

   dsmc incremental /usr -snapshotroot=/snapshot/day1

For example, consider an application that takes a snapshot of the c: drive and mounts it as the NTFS junction point \\florence\c$\snapshots\snapshot.0. If you back up this data by using the following command, a unique file space that is called \\florence\c$\snapshots\snapshot.0 is created on the server.

  dsmc incremental \\florence\c$\snapshots\snapshot.0

However, you might want to associate the snapshot data with the data already processed for the c: drive (\\florence\c$). Using the snapshotroot option, you can associate the data with the file space corresponding to the c: drive (\\florence\c$) on the Tivoli Storage Manager server:

  dsmc incr c: -snapshotroot=\\florence\c$\snapshots\snapshot.0
  -or-
  dsmc incr \\florence\c$ -snapshotroot=\\florence\c$\snapshots\
    snapshot.0

On a subsequent day, you can back up a snapshot that was written to an alternative location, but managed under the same file space on the server: AIX operating systems

   dsmc incremental /usr -snapshotroot=/snapshot/day2

  dsmc incr c: -snapshotroot=\\florence\c$\snapshots\snapshot.1

You can perform incremental backups, selective backups, or archives of a single directory, directory structure, or single file by using the snapshotroot option. In all instances, the snapshotroot option must identify the root of the logical volume that was created by the snapshot. For example: AIX operating systems

   dsmc incremental /usr/dir1/* -subdir=yes 
     -snapshotroot=/snapshot/day1
   dsmc selective /usr/dir1/sub1/file.txt 
     -snapshotroot=/snapshot/day1
   dsmc archive /usr/dir1/sub1/*.txt 
     -snapshotroot=/snapshot/day1

  dsmc incr c:\dir1\* -subdir=yes  -snapshotroot=\\florence\c$\
    snapshots\snapshot.1
  dsmc sel c:\dir1\sub1\file.txt -snapshotroot=\\florence\c$\
    snapshots\snapshot.1
  dsmc archive c:\mydocs\*.doc -snapshotroot=\\florence\c$\
    snapshots\snapshot.1

If you want to include or exclude specific file specifications, the include and exclude statements should contain the name of the file system that was the source of the snapshot (the /usr file system), and not the name of the target of the snapshot (/snapshot/day1). Doing this allows you to preserve a set of include and exclude statements regardless of the name of the logical volume to which the snapshot is written. The following are examples of include and exclude statements.

  include /usr/dir1/*.txt 1yrmgmtclass
  exclude /usr/mydocs/*.txt

If you want to include or exclude specific file specifications, the include and exclude statements should contain the name of the file system that was the source of the snapshot (the c: drive), and not the name of the target of the snapshot (\\florence\c$\snapshots\snapshot.1). Doing this allows you to preserve a set of include and exclude statements regardless of the name of the logical volume to which the snapshot is written. The following are examples of include and exclude statements.

  include c:\dir1\.../*.txt lyrmgmtclass
  exclude \\florence\c$\mydocs\*.doc

The following include-exclude statements are not valid because they contain the name of the snapshot: AIX operating systems

  include /snapshot/day1/dir1/*.txt 1yrmgmtclass
  exclude /snapshot/day1/mydocs/*.txt

  include \\florence\c$\snapshots\snapshot.1\dir1\...\
    *.txt 1yrmgmtclass
  exclude \\florence\c$\mydocs\*.doc

You must use the snapshotroot option with a single file specification for an incremental, selective, or archive operation. You cannot specify multiple file specifications or no file specifications. For example, these commands are valid: AIX operating systems

  dsmc incremental /usr -snapshotroot=/snapshot/day1
  dsmc incremental /usr/dir1/* -snapshotroot=/snapshot/day1

  dsmc incr c: -snapshotroot=\\florence\c$\snapshots\snapshot.0
  dsmc incr c:\dir1\* -snapshotroot=\\florence\c$\snapshots\
    snapshot.0

The following command is invalid because it contains two file specifications: AIX operating systems

  dsmc incremental /usr/dir1/* /home/dir2/* 
    -snapshotroot=/snapshot/day1

  dsmc incr c:\dir1\* e:\dir1\* -snapshotroot=\\florence\c$\
    snapshots\snapshot.0

The following command is invalid because it contains no file specification: AIX operating systems

  dsmc incremental -snapshotroot=/snapshot/day1

  dsmc incr -snapshotroot=\\florence\c$\snapshots\snapshot.0

Notes:

Ensure that the snapshotroot option references a snapshot of the correct volume. Ensure that snapshotroot location refers to the root of the snapshot. If these rules are not followed, unintended results, such as files that expire incorrectly, can result.
If you specify the filelist option and the snapshotroot option, all files that are specified in the filelist option are assumed to be in the same file system. If there are entries in the filelist in a different file system, they are skipped and an error is logged. If the filelist contains files that were created in the file system after the snapshot was taken, these entries are also skipped, and an error is logged.
You cannot use the snapshotroot option with any backup command, such as backup image, or backup systemstate, and so on.
You cannot use the snapshotroot option with the snapdiff option.
Use the snapshotroot option with caution if you are using the Tivoli Storage Manager journal-based backup feature. Since there is no coordination between the Tivoli Storage Manager journal and the vendor-acquired snapshot provider (VSS), unwanted behavior can occur with journal notifications received after the snapshot occurs. For example, files might not be backed up, or they might be backed up redundantly to the Tivoli Storage Manager server.
You can use the snapshotroot option with the preschedulecmd and postschedulecmd options, or in an automated script that you run with the Tivoli Storage Manager client scheduler.

Supported Clients

This option is valid for the following clients:

UNIX and Linux clients except Mac OS X.
All Windows clients.

Syntax


>>-SNAPSHOTRoot = - --snapshot_volume_name---------------------><

Parameters

snapshot_volume_name: Specifies the root of the logical volume that is created by the independent software vendor snapshot application.

Examples

Command line:: dsmc incremental /usr -SNAPSHOTRoot=/snapshot/day1
Command line:: dsmc incr c: -SNAPSHOTRoot=\\florence\c$\snapshots\snapshot.0