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Live File Recovery

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 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.

Before You Begin

  • To browse and recover files from a guest VM running Windows 2012 R2, select a VSA proxy and MediaAgent that is Windows Server 2012 R2 or later.
  • To restore UNIX files for ext4, XFS, JFS, HFS, HFS Plus, or Btrfs file systems, 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.
  • 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. The MediaAgent that performs the browse must have access to the library and media that are required for the restore operation.
  • To enable Live File Recovery even when the Enable Granular Recovery option is selected, 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. A MediaAgent running Windows 2012 or later, with the Virtual Server Agent installed and with the Windows deduplication role enabled, must be used as the VSA proxy when restoring the dehydrated files.
  • 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.
  • Metadata collection and live browse are not supported for Windows Storage Spaces. To retrieve guest files from Storage Spaces, restore the full virtual machine or virtual machine disk files.
  • 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 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 (each volume spanning only a single disk)