VSS backup requirements

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You can plan your VSS backup strategy to optimize the performance of your backup operations and to avoid potential problems. Follow these guidelines when you plan your VSS backups:

  • Planning VSS backups
    • Use custom-application VSS backups and files-system data VSS backups for only NTFS and ReFS volumes.

      For file system and custom application data, data is restored at the volume level. When a file system or custom application data is restored, all files from the VSS snapshot backup are restored to their original location.

    • Use single hardware Logical Unit Numbers (LUN) for log files, system files, and database files.
    • Use basic disks, which are initialized for basic storage. A basic disk consists of basic volumes, such as primary partitions, extended partitions, and logical drives. Do not use dynamic disks.
    • If you plan to keep VSS snapshot backups only on local shadow volumes, know how to implement the configuration options of your VSS hardware provider.

      For example, if your VSS hardware provider supports a full-copy snapshot versus a copy-on-write snapshot mechanism, full-copy type implementations have greater disk storage requirements. However, full-copy type implementations do not rely on the original volume to restore the data and are less risky. Copy-on-write implementations require less disk storage but rely on the original volume to restore the data.

    • Do not place multiple volumes on the same LUN. Configure a single volume, single partition, and single LUN as one-to-one.
    • Do not set the ASNODENAME option in the dsm.opt file when you use IBM Storage Protect Snapshot. Setting the ASNODENAME option can cause VSS data backups and VSS restore operations to fail.
  • Running parallel VSS backups

    If you need to run parallel VSS backups, do the following:

    • Stagger the start time of the backups by at least 10 minutes. This interval ensures that the snapshot operations do not overlap.
      Attention:
      If backup operations overlap, a VSS timeout error may occur and the second backup request may fail. Therefore, it is recommended to stagger the start time of the backups.
    • Configure the parallel instance backups so that snapshots of the same volumes are not created.
    • Ensure that parallel backups do not create a snapshot of the same LUN.