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Chapter 4: Storage
Viewing the Snapshot Reserve Details
Network Storage System (NSS) Administrator Guide
Chapter
4
Viewing the Snapshot Reserve Details
You can configure the NSS6000 series NAS to take snapshots of the data on an existing volume.
When you create a snapshot, a backup of each of the shares on the volume is created and is
available within the file directory to which the end user has access. The advantage of a snapshot
over a backup is that a snapshot is user-accessible and can be used for quick file recovery resulting
from end user error (such as, an accidentally deleted file). A backup is only accessible to the
administrator through the NSS configuration interface and restoring data through the backup can
be timely. Backups are usually used to restore the system from a major system failure.
Snapshots can be taken at various time intervals (such as hourly, daily, and so on). Each time a
snapshot is taken, the previous snapshot is overwritten. You can also configure multiple snapshots to
occur at different time intervals for the same volume. For example, you might want to capture a
snapshot each hour, weekly, and bi-weekly. In this case, the volume has three separate snapshots.
Each snapshot is overwritten when the next snapshot of the same frequency is taken. To ensure data
integrity, during the creation of the snapshot (the duration is approximately a few seconds), no
writes can occur to the share.
The snapshot reserve is the amount of space that you want to allocate to the snapshot on the
associated array. Once set, this space is not available for other storage use. The recommended
amount of a reserve is generally between 10 to 20% of the total volume size. Note that if the period
of time between snapshots is greater, the amount of the reserve should be greater. Or, if there is a
heavy amount of activity on the volume, set a higher reserve. This is due to the snapshot reserve
being used to store the changes to the volume contents since the last time the snapshot was taken.
NOTE:
This feature is only available on the NSS6000 series NAS.
