Archiving snapshots to offline media

Archiving Manager backups

Offline archiving of virtual disks to archive media, such as NearStore technology or other media, is a good way to protect and retain data by using an alternate storage method. It is a good practice to back up snapshots to offline media kept in offsite storage for use in disaster recovery.

A backup consists of the snapshots of the virtual disk drives that store the data files. NDMP or Dump are the most efficient methods for creating archives of the virtual disk drive files.

Backing up the virtual disk file

Using any popular Windows backup software package or the dump command on the filer, back up the virtual disk file itself from a snapshot.

It is important to back up a virtual disk file that is in a snapshot that was created by SnapManager. Because virtual disks from multiple hosts can be stored on the same filer volume, only virtual disks that belong to the host that created the SnapManager snapshot are consistent. All virtual disks within that snapshot that belong to other hosts are not consistent. For this reason, it is recommended that you dedicate your filer volumes to individual hosts.

As part of the snapshot process, the file system (NTFS) is flushed to disk and the disk image in the snapshot is in a consistent state. This cannot be ensured if the snapshot was created outside the control of SnapManager (that is, at the filer console, using SnapDrive, or using the FilerView® interface, or rsh), or if the virtual disk file in the active file system is backed up.

Restoring archived VLDs

Restore the virtual disk file from your archive media to the active file system. After the file is restored, use the SnapDrive management interface to connect to the virtual disk file using its original drive letter. For more information about how to perform a recovery from offline archive, see your backup application software documentation or, if you are using the dump or NDMP command, see the Data ONTAP Data Protection Guide appropriate for your version of Data ONTAP.

Restoring archived LUNs

If you are using the NDMP or dump command, or the CIFS option, restoring LUN-type virtual disk files is identical to restoring VLD-type virtual disk files. Where the process might differ is if the LUN environment is leveraging FC-AL-based backups. For more information about LUN backups, see the Data ONTAP System Administrator's Guide appropriate for your version of Data ONTAP.