Online backup and recovery

About online backup and recovery

Data ONTAP creates online data backups to enable online data recovery. Online backup refers to backup data that is stored on disks rather than on tape. Data stored on disk is thus available for quick restoring in event that disaster recovery operations are necessary.

Online backup and recovery solutions include: SnapShot, SnapMirror, SnapRestore, SnapVault, SyncMirror and the vol copy command.

The SnapShot feature enables you to schedule weekly, daily, or hourly online backups. Snapshot technology makes online point-in-time copies in the same volume as the original data and enables users to recover their own deleted or modified files without assistance from a system administrator.
The SnapRestore feature restores an entire volume to the state recorded in a previously created snapshot with maximum speed and disk space efficiency.
The SnapMirror feature performs regularly scheduled automated file system snapshot replication of a volume or qtree onto another volume or qtree on the same or a separate filer.
The SnapVault feature protects the data in one or more qtrees in a series of snapshots stored on a separate filer. SnapVault maintains an online, asynchronous, permanently read-only replica of the qtree data. SnapVault backup and snapshot creation runs on an automated schedule.
Note
SnapVault, in addition to providing backup to NetApp filers, also provides direct backup of non-filer storage systems, such as servers running Windows NT, Windows 2000, Solaris, or HP-UX.
SyncMirror provides continuous real-time mirroring of data between two partner volumes on a shared or partner filer system.
You can also use the vol copy command to snapshot and copy file systems to separate volumes or filers manually or by means of a script. You can use the ndmpcopy command to copy any subtree to any location on any filer.
The MetroCluster feature provides SyncMirror continuous mirroring over extended distances (500 meters to 10 kilometers).

You can use these online data backup and recovery systems to supplement tape backup and recovery.

Advantages of online backup and recovery

Online backup and recovery protection gives you the following advantages over tape archives alone:

Speedy backups and restores greatly reduce backup time requirements.
Backups can be made more frequently because they are faster.
It is easy to recover a particular file, directory, or volume from an online backup.
Disaster recovery is quicker with online mirroring and restores.
Data availability is higher because of the high speed of data recovery.
More data can be backed up in less time.

Disadvantages of online backup and recovery

Online snapshot data protection has the following disadvantages over tape archives:

Online data protection is physically vulnerable. Filers and disk shelves are vulnerable to physical catastrophes.
Online data protection consumes resources, such as disk space, that could be used for day-to-day activities.

Online backup and restore methods

To find detailed information about Data ONTAP data protection and online backup and recovery methods, consult the following table.

Method	Chapter
Using snapshots to make a read-only image of a file system on the same disk	Chapter 2, Snapshot Management
Using SnapRestore to restore data to a corrupted volume from a previous snapshot	Chapter 3, Data Reversion Using SnapRestore
Using SnapMirror to maintain a replica of one volume in another volume	Chapter 4, Data Protection Using SnapMirror
Using SnapVault to keep copies of volumes on the server, from which individual qtrees are available at any time to the client	Chapter 5, Data Protection Using SnapVault
Using the `vol copy` command to copy data from one volume to another	Chapter 6, Volume Copy
Using SyncMirror to maintain two identical copies of a volume at all times	Chapter 7, Mirrored Volume Management Using SyncMirror