HP StorageWorks NAS 1000s, Administration Manual, Page: 157 / 172

Backup Management
157 NAS 1000s Administration Guide
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Server name
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IP addresses
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Gateways
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DNS servers
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NIS servers
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User mapping database
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Storage setup
— Member storage units (LUNs)
— Share names, paths, and access permission settings
This information greatly increases the ability to quickly and accurately recover from
catastrophic failures such as fires, weather disasters, theft, and complete hardware failure.
Snapshots and Quick Online Restores
Persistent Storage Manager (PSM) provides instant data recovery from hundreds of online
snapshots. Once the first snapshot is taken PSM monitors all drive activity retaining the
deleted data required to recreate the last snapshot. Individual files, groups of files, folders,
groups of folders or complete volumes can be restored. Security rights and privileges, as well
as file and directory attributes, remain in effect as they were at the time the snapshot was
created.
Snapshots can be used as a convenient source of data for a backup. There are some
applications that must be stopped before backups are made. A backup requires that the file
system is recorded in a consistent state, where no changes occur during the backup. Because
snapshots are created in a matter of seconds and maintain a consistent view of the file system
from that point on, snapshots can drastically reduce the amount of time applications must be
paused or shut down during backup operations. The NAS device facilitates automatically
creating snapshots at any given time.
Caution: Snapshots should be considered an additional convenience for restores, not a
replacement for tape backup. In the event of disk failures, snapshots can be lost along with
the original data. Snapshots will be automatically deleted without warning by PSM to
regain space when disk space is low.
Although snapshots should never be considered a replacement for regular data backup to
removable media, they can be a highly convenient feature for immediate, tapeless recoveries.
If a file is accidentally deleted or corrupted, it can be recovered quickly by accessing the
snapshot, selecting the file or directory, and copying it back to its original location on the
volume.
To use the snapshot capability for a quick online restore, take a snapshot on a regular basis or
before the source disk is altered. This ensures a backup of all the original files, applications,
and configurations.