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Live File Recovery for VMware

Live file recovery provides expanded file system support, including ext4, and enables live browse of backup data without requiring granular metadata collection during backups. This option supports block-level restores of files and folders from backups of Windows VMs that use NTFS, ReFS, FAT, and FAT32 file systems, and of UNIX VMs that use ext2, ext3, ext4, XFS, JFS, HFS, HFS Plus, or Btrfs file systems.

Live file recovery can also be used when reducing backup times is a priority. This is a tradeoff; using this feature reduces backup time but increases the time required to browse files and folders.

For Windows guest VMs, the Windows MediaAgent that is used for browse and restore operations must have the Virtual Server Agent installed.

For Linux guest VMs, a File Recovery Enabler for Linux can be used to browse and restore data from backups of UNIX VMs.

Before You Begin

  • To browse and recover files from a guest VM running Windows 2012 R2 or later, select a VSA proxy and MediaAgent running Windows Server 2012 R2 or later.
  • To browse and recover files from a guest VM running Windows 10, select a VSA proxy and MediaAgent running Windows Server 2016.
  • To restore UNIX files for ext4, XFS, JFS, HFS, HFS Plus, or Btrfs file systems in addition to ext2 and ext3 files, you must deploy and use a File Recovery Enabler for Linux to access the data in the backup. See Deploying a File Recovery Enabler for Linux.
  • For Commvault Service Pack 7 and later, MediaAgents that are able to act as File Recovery Enablers are automatically configured.
  • When you perform a live browse operation on Linux files and folders, the Client tab shows logical volumes as volume groups rather than mount paths.
  • To support live file recovery when the Virtual Server Agent and MediaAgent are deployed on different machines, the Virtual Server Agent must also be installed on the MediaAgent, even if a different MediaAgent is used for data movement. Otherwise, the MediaAgent is not included in the Use MediaAgent list in the Advanced Options tab of the Browse and Restore Options dialog box. You must provide data access for the MediaAgent in one of the following ways:
  • To enable live file recovery even when the Collect File Details option is selected for a subclient, you can configure the nEnforceLivebrowse additional setting on the Virtual Server Agent (VSA) proxy.

Considerations

  • Live file recovery is only supported for recovery from backups using magnetic disk libraries, and is not supported from backups to tape libraries or virtual tape libraries.
  • Browsing fails if the file system on the source VM for the backup is not supported by the File Recovery Enabler for Linux.
  • Browsing speed is affected by network latency and the complexity of the file system being browsed.
  • Initial mount during browse may take some time if the VM snapshot contains an inconsistent file system that requires fsck (file system check). A restore that follows the browse in quick succession does not incur that overhead because it reuses the mount point.
  • Some special files from UNIX systems cannot be restored to a Windows system. These include symbolic link files, socket files, character device files, block files, and pipe files (FIFOs).
  • A virtual machine that contains the File Recovery Enabler for Linux can be included in backups, and the full VM can be restored; but you cannot recover files from the VM.
  • Use live file recovery to restore files that have been dehydrated by Windows deduplication. The Windows version of the VSA proxy and MediaAgent must be the same as or later than the Windows version of the VM for which files are being restored. For example, a MediaAgent running Windows 2012 R2 or later, with the Virtual Server Agent installed and with the Windows deduplication role enabled, must be used as the VSA proxy when restoring dehydrated files from a Windows 2012 R2 VM.
  • Logical volume manager (LVM) metadata processing for volumes encrypted using BitLocker is currently not supported. Decrypting contents of such volumes may not be feasible during browse or restore operations because decryption requires a recovery password or a decryption key. Because enumeration for the volume fails, a file-level browse operation for the encrypted volume cannot display file information.
  • If there is no activity on the VM for a specified time (10 minutes by default), the browse times out and the VM is unregistered. Once the cleanup is done, the restore job is marked as complete.
  • For block-level restores, in addition to the restore job, the Job Controller launches a persistent recovery job that opens a common pipeline, enabling multiple extent recall requests to be submitted as a group. The default timeout for a persistent recovery job is 24 hours. For block-level restores using the Virtual Server Agent, the persistent recovery job remains open for 24 hours and can be used for subsequent block-level restores that use the same proxy.
  • The MediaAgent that you use for live browse operations of an ReFS volume must support the version of the ReFS volume on the guest VM. For example, to live browse and restore files from an ReFS volume from a backup of a Windows Server 2016 VM, you must use a MediaAgent running on Windows Server 2016 or later. To browse and restore files from an ReFS volume from a backup of a Windows Server 2019 VM, use a MediaAgent running on Windows Server 2019 or later.
  • Windows Storage Spaces: You can perform a live browse to view and restore guest files and folders, with the following requirements and limitations:
    • The VSA proxy and MediaAgent that are used for the live browse must be running on Windows Server 2012 or later.
    • For a Windows 2016 guest VM, you must use a VSA proxy and MediaAgent that run on Windows 2016 or later.
    • The MediaAgent that is used for the live browse cannot be part of a clustered environment.
    • You cannot simultaneously browse two cloned VMs that use the same storage space information.
    • Live browse of Windows storage spaces is only supported for streaming backups, auxiliary copies, and backup copies, and not directly from IntelliSnap backups.
  • For Linux:
    • When used with agentless restores, the Restore ACLs option only restores basic user/group/world permissions and timestamps. Advanced permissions are only restored when using a guest agent together with a File Recovery Enabler for Linux.
    • The Preserve Source Paths option is not supported when you are restoring files or folders from a virtual machine.
    • Permissions for guest files and folders are retained only when the user running the restore operation has permissions to change group ownership on the restored files and folders. If the user does not have change group ownership permissions, the restored files and folders are owned by the user who performed the restore.
    • You cannot restore an empty folder unless you restore the parent folder. When you restore a parent folder all other folders contained in the parent folder are also restored.
    • Symbolic links can be restored if the source files are also restored, but they will use the timestamp of the restore operation instead of the original timestamp. If the source files are not restored, symbolic link files are restored but without links; as a result the linked data cannot be read.
    • Hard link files can be restored; if source files are also restored any corresponding link files use the same index node (inode).
    • For UNIX file restores, the restore operation uses the File Recovery Enabler for Linux that hosts the backup (if one is available) or the default File Recovery Enabler for Linux for the virtual server instance.
    • The following file systems are supported when using a File Recovery Enabler for Linux:
      • ext2
      • ext3
      • ext4
      • XFS
      • JFS
      • HFS
      • HFS Plus
      • Btrfs

        Notes:

      • Live browse and file recovery operations are not supported for XFS realtime subvolumes.
      • With Service Pack 8 or later, live browse and recovery is supported for subvolumes of Btrfs file systems.

Last modified: 4/11/2019 8:18:04 PM