Adaptec 5325301638 - Snap Server 4500 NAS, Руководство администратора

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Snap Server Administrator Guide 55 Snap Server Administrator Guide 55
Chapter 7
Snapshots
A snapshot is a consistent, stable, point-in-time image of a volume used for
backup purposes. Snapshots can satisfy short-term backup situations such
as recovering a file deleted in error, or even restoring an entire file system,
without resorting to tape. Perhaps more importantly, snapshots can be
incorporated as a central component of your backup strategy to ensure that
all data in every backup operation is internally consistent and that no data
is overlooked or skipped.
Topics in Snapshot Management:
• Snapshot Management and Usage
• Estimating Snapshot Pool Requirements
• Adjusting Snapshot Pool Size
• Accessing Snapshots
• Coordinating Snapshot and Backup Operations
Related Information:
• Isolate iSCSI Disks from Other Resources for Backup Purposes
Snapshot Management and Usage
This section describes snapshot components and dependencies.
The Snapshot Pool
Snapshot data are stored on a RAID in a snapshot pool , or space reserved within the
RAID for this purpose. Each RAID on the system contains only one snapshot pool.
This pool contains all snapshot data for all volumes on the RAID. For more
information, see “Estimating Snapshot Pool Requirements” on page 57.
Rolling a Volume Back to a Previous State
If you need to restore an entire file system to a previous state, you can do so without
resorting to tape. The snapshot rollback feature allows you to use any archived
snapshot to restore an entire file system to a previous state simply by selecting the