Veritas NetBackup™ Snapshot Client Administrator's Guide

Note the following restrictions:

• For snapshots using Storage Checkpoints, Instant Recovery supports file systems with the Version 4 disk layout or later. Older disk layouts must be upgraded to Version 4 or later.

• No-data Storage Checkpoints (those containing file system metadata only) are not supported.

• Instant Recovery snapshots must not be manually removed or renamed, otherwise the data cannot be restored.

• Instant Recovery does not support the VxVM, FlashSnap, and VVR snapshot methods when used with VxVM volume sets.

• On Linux, Instant Recovery is not supported by disk-array based snapshot methods.

• For Instant Recovery backups of data that is configured on VxVM volumes on Windows, the VxVM volume names must be 12 characters or fewer. Otherwise, the backup fails.

• Any media server that is used in an Instant Recovery backup must have full server privileges.

  See Giving full server privileges to the media server.

• Instant Recovery restores can fail from a backup that a FlashSnap off-host backup policy made.

  From a policy that was configured with the FlashSnap off-host backup method and with Retain snapshots for Instant Recovery enabled, the backups that were made at different times may create snapshot disk groups with the same name. As a result, only one snapshot can be retained at a time. In addition, NetBackup may not be able to remove the catalog images for the snapshots that have expired and been deleted. It appears that you can browse the expired snapshots and restore files from them. But the snapshots no longer exist, and the restore fails with status 5.

• For Instant Recovery, Veritas recommends that a primary volume be backed up by a single Instant Recovery policy. If the same volume is backed up by two or more Instant Recovery policies, conflicts between the policies may occur during snapshot rotation. Data loss could result if the policies are configured for snapshots only (if the policies do not back up the snapshots to separate storage devices).

  Consider the following example: Two policies use the same snapshot device (or VxFS storage checkpoint) to keep Instant Recovery snapshots of volume_1.

  • Instant Recovery policy_A creates a snapshot of volume_1 on the designated snapshot device or storage checkpoint.

  • When Instant Recovery policy_B runs, it removes the snapshot made by policy_A from the snapshot device or storage checkpoint. It then creates its own snapshot of volume_1 on the snapshot device or storage checkpoint. The snapshot created by policy_A is gone.

  Note:

  Even if each policy has its own separate snapshot devices, conflicts can occur when you browse for restore. Among the available snapshots, it may be difficult to identify the correct snapshot to be restored. It is therefore best to configure only one policy to protect a given volume when you use the Instant Recovery feature of NetBackup.