3.5.4 Single Item Restore From Snapshot

Single item restore from a Snapshot uses a temporary volume and restores each file from the Snapshot so that only the necessary files are recovered.
Single item restore can be executed only when the Number of Snapshot Generations is set to "1" or more in the virtual machine backup policy.

The procedure for executing Single item restore from a Snapshot is as follows:

Information

Operating system operations and expression on screen may vary with the version level of the operating system.

Determine the "Snapshot to Restore", "Disk where the Files to Restore Exist", and "Temporary Volume Hold Time".
- Snapshot to Restore
  Determine the Snapshot to restore. Only Snapshots created with ETERNUS SF system can be restored.
  Only one Snapshot can be selected. If a restoration from multiple Snapshots is necessary, repeat the procedure described in this section for each Snapshot.
  Note
  In a single instance of Single item restore, restoration from multiple Snapshots cannot be executed simultaneously. When files are restored from multiple Snapshots, the temporary volume must be repeatedly created and deleted for each Snapshot.
  If you want to delete the temporary volume before the temporary volume hold time is exceeded, contact the storage administrator.
- Disk where the Files to Restore Exist
  Determine the disk (VMDK filenames) within the Snapshots where the files to restore exist.
  Multiple disks can be selected.
  Note
  The same number of temporary volumes are used as the number of disks selected here. For this reason, check whether there is sufficient space in the SCSI controllers of the virtual machine where the temporary volumes are connected.
  If there is no space in the SCSI controllers of the virtual machine, temporary volumes cannot be connected to the virtual machine. Add a SCSI controller or prepare a free controller from within the existing controllers. Refer to the VMware manuals for the method of adding SCSI controllers.
  If a free SCSI controller still cannot be prepared, reduce the number of selected disks.
- Temporary Volume Hold Time
  Determine the time to keep the temporary volume connected to the virtual machine. The time can be specified with a range of 1 - 99 hours.
  Because the temporary disk is automatically deleted when the specified time expires, estimate and determine the time required for the file recovery work.
Notify the storage administrator of the information determined in step 1 to request Single item restore (connection of temporary volume to virtual machine).

A work completion notification is received from the storage administrator.

Temporary volumes where the disk content is copied within the Snapshot are connected to the virtual machine. A temporary volume is created as the following attributes in the same VVOL datastore as Snapshot targeted for restore.

Attribute (*1)	Content
Disk Provisioning	Thin Provisioning
Virtual Device Node	SCSI
Disk Mode	Independent-type
VMDK File Name	ESF_TEMP_sourceVmdkFileName
Connection Destination	Located in order from controller 0(SCSI 0:x)

*1: The term of each item may vary with the version level of vCenter Server.

Rescan the disk and partition.
- For Windows
  On the virtual machine, rescan the disk from Disk Management.
  Note
  On the Disk Management screen, it may be prompted to initialize disk for the temporary volume. When prompted to initialize disk, cancel the rescan. Initializing disk causes all the contents of the temporary volume to be cleared.
- For Linux
  On the virtual machine, rescan the disk and partition.
  Example
  On the virtual machine, execute the following command:
```
sfdisk -R deviceName
```
  deviceName: Temporary volume device name (/dev/sd*)
Mount a temporary volume on the virtual machine.
- For Windows
  On the virtual machine, place a temporary volume online from Disk Management to assign a drive letter.
- For Linux
  On the virtual machine, mount a temporary volume by executing the "mount" command.
Copy the files necessary to recovery from the temporary volume to the business volume.
Unmount the temporary volume from the virtual machine.
- For Windows
  On the virtual machine, place the temporary volume offline from Disk Management.
- For Linux
  On the virtual machine, unmount the temporary volume by executing the "umount" command.

Note

In Single item restore, disks are automatically added to the virtual machine. Therefore, if a compatible device is in use, and when performing a system restart with an existing temporary volume, device name misalignments may occur. Using device names that do not cause device name misalignments is recommended. For information regarding device name misalignments, refer to the OS manuals.
Do not create Snapshots while a temporary volume exists. The temporary volume could not be removed. Create Snapshots after removing the temporary volume.
Single item restore from a Snapshot of backed up Windows dynamic disks is unsupported.