Restore Data - Image Level
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Overview
Restore Considerations for this
Agent
Restore Destinations
The following page describes the agent-specific restore options. Additional restore options are accessible from the Related Topics menu.
The Image Level iDataAgent performs the following types of restore operations:
- File Level Restore - You can browse the files/folders in your backup and
select the files/folders you want to restore.
- Volume Level Restore - You can browse the volumes you have backed
up and select a volume to restore. The following restore options for volumes
are available for the Image Level iDataAgent. These options are
available from the
Restore
Options dialog box.
- Physical Volumes - This option enables you to restore the selected
content as a physical volume.
- VMDK files (Windows only) - This option enables you to restore the selected
volume as a virtual machine file.
- Virtual Hard Disk file (Windows only) - This option enables you to restore the
selected content as a virtual hard disk file.
When restoring data, you can, if desired, restore the data to a file system type
that differs from the type in which it originated. For example, you can restore
NTFS data to a FAT file system and restore FAT data to an NTFS file system. FAT
file systems do not support Discretionary Access Control Lists (DACL); therefore,
any NTFS data that you restore to a FAT partition loses its original access privileges.
Conversely, when FAT file system data is restored to an NTFS file system, the restored
data inherits the DACL of the destination directory.
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Before performing any restore procedures for this agent, review the following
information:
General
- Review the general restore requirements described in
What You Need to Know Before Performing a Restore.
- Since Image Level restores a portion of Volume Information to the MediaAgent
Index Cache, if encryption was enabled when the data was backed up, the Volume
Information will be encrypted as well. This requires a Pass-Phrase on the MediaAgent
to decrypt during the restore. There are two ways to handle this:
- For increased logging of activities during data recovery operations, the
dEnableIRestoreLog
registry key can be created.
- Although you can use the Image Level iDataAgent to back up volumes of a
clustered shared disk, you cannot use the Image Level iDataAgent to restore
directly to the volumes of a clustered shared disk.
- Supported only for certain operating systems and file system types; see
Supported Data
Types.
- The Image Level and Image Level ProxyHost iDataAgents
on Unix can
perform a File Level Restore
only when the OS of the Client computer and the MediaAgent are the same.
- For a Windows MediaAgent, the Index Cache folder must reside on an NTFS
partition.
- If metadata was not collected during a backup, a File Level restore cannot
be performed. This might result from having selected the
Skip
Metafile Creation option in the Advanced Backup Options screen, or as a
result of failure to collect metadata during the backup, in which case the system
generated an Event Message warning of the failure.
- Do not restore:
- hidden objects
- system files
- recycler files
- Image Browse is not supported. A no-image browse operation returns the most
recent version of the data that existed back to the most recent full backup,
rather than returning an image of the specified entity (i.e., file system/directory).
To perform a File Level Restore of an entity to a point in time, you will need
to Browse back in time, to the point
in time you want to restore.
- When a File Level restore is started, metadata is restored prior to the
actual restore of files, and during this time, a message might indicate the
Index Cache is being restored, although it already exists. Also, the media containing
this metadata will be mounted into the library even if this media does not contain
the data from the full backup.
- As noted in the
Image Level
Backup Considerations, if the cluster size (allocation unit) on the disk
that you backed up was less than 1024 bytes, a file level restore job will not
complete successfully.
- For a Volume Level Restore, you must select the Browse only Volumes
option in the Browse Options dialog box, or the restore operation will
be a File Level Restore.
- Do not run Volume Level restore if destination volume contains OS files.
- When performing a Volume Level Restore, the destination volume will adopt
the file system type of the restored data. Thus, for instance, if you restore
an NTFS volume to a FAT destination volume, the destination volume will be NTFS
as a result of the Volume Level Restore.
- When restoring a volume changes its file system type (see
Supported Data
Types), sometimes Windows Explorer may still show the volume having the
same file system type as before the restore, even though Computer Management
shows the new (correct) type. After a reboot, Windows Explorer will show the
correct file system type.
- The destination volume must be at least as large as the volume from which
the data was backed up. This is true regardless of the amount of data that is
actually restored. For example, if you back up a 10 GB volume that contains
100 MB of data, you can only restore that data to a volume that is 10 GB or
larger. The restore operation will fail if the destination volume is smaller
than the source volume. We recommend that you restore data to a volume that
is at least 1 MB larger than the source volume.
Windows Logical Disk Manager
(LDM) displays the size of a volume in round numbers. Consequently, LDM may
display the same size for two volumes with slightly different block counts.
To get the exact size of a volume, open the Windows Explorer, right-click the
volume, and select Properties. The volume's capacity in bytes is its
exact size.
If no destination volume is specified, the system attempts to restore to
a volume on the Destination Computer with the same name as the one being
restored. If no such volume exists, the restore operation fails.
- For Image Level on Unix, the fsck command
is automatically run after restoring a volume. This functionality can be disabled
through the use of the
dDisableFsck
registry key.
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By default, the Image Level iDataAgent
restores a volume or file(s) to the client from which it originated; this is referred
to as an in-place restore. If desired, you can also restore the data to a different
Image Level client. Keep in mind the following considerations when performing such
restores:
- The destination client must reside in the same CommCell as the client whose
data was backed up.
- Each of these restore destination types are available for both Volume Level
restores as well as File Level restores, both for Windows and Unix.
The following section enumerates the types of restore destinations that are supported
by the Image Level iDataAgent. See
Restore/Recover/Retrieve Destinations - Support for a list of Agents supporting each restore destination
type.
For File Level Restores only, besides restoring data to a client computer’s local
drive, you can also restore data to a UNC path (Windows) or an NFS-Mounted File
System (Unix). (See
Restore to Network Drive/NFS-Mounted File System for comprehensive information.)
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