VSS data backups
You can store VSS backups on local VSS shadow volumes, or, when integrated with IBM Storage Protect, in IBM Storage Protect server storage.
VSS backups eliminate the need for the server or file system to be in backup mode for an extended time. The length of time to complete the snapshot is measured in seconds, not hours. In addition, a VSS backup allows a snapshot of large amounts of data at one time because the snapshot works at the volume level.
You must ensure that sufficient space is available for the snapshot at the storage destination. Both storage destinations require space to store the snapshot until the data transfer to the IBM Storage Protect server is complete. After the data transfer to the server is complete, VSS backups that are stored locally on VSS shadow volumes are directly accessible by the system. The snapshot volume is released and the space can be reused.
- For data that is backed up to local VSS shadow volumes, the snapshot backup is on the shadow copy volume.
- For data that is backed up only to IBM Storage Protect server storage, a local snapshot backup is run and the data on the local snapshot volume is sent to the IBM Storage Protect server.
- For data that is backed up to VSS shadow volumes and IBM Storage Protect server, the local snapshot volume is retained as a local backup after the transfer to the IBM Storage Protect server is complete.
If you store VSS backups both locally and to IBM Storage Protect server, and the maximum number of local backup versions to be maintained is reached, the oldest local backup version expires to create the new snapshot for the backup to IBM Storage Protect server storage. The maximum number of local backup versions that are maintained is set in the IBM Storage Protect policy.