Installation guide

Configuring Your IP4700 Device for Use with Backup Software
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Configuring Veritas NetBackup Software
the snap. The backup provides a consistent image with none of the
file changes that take place during the backup.
Be sure to define enough space for the snap area. Other applications
can also use the copies. Fast incremental, described in the next
section, and SnapView use the same area. Up to 85% of the volume
can be a reserve area. While you can define the space either initially
or later, we recommend that you define it initially so that you can set
it up and increase it. If you build it later, the space may not be large
enough. To set up the area or to enlarge it, it must be free of data, that
is, it cannot contain any snap images.
We recommend that you plan for snap images. Also, provide enough
space in the snap area to accommodate changes made to files for the
duration of the backup. Consider the following when sizing the snap
copy areas:
• Heavy use of reads and writes
• Number of concurrent snaps
• Rate of data change
• Concurrent Fast Incremental backups
SnapView copies only the blocks that change. It moves the blocks into
the snap area, which makes space for new data. For example, if you
request to read block A, you will see the file as it existed at the time
you copied block A to the snap save area. You can create another snap
image for a later time, and can distinguish between them by the day
and time, for example, Monday, 8:00. You can have up to 92 current,
active snap images. You can write to the latest snap image with
pointers to the earlier snap images.
To use snapView, you must turn on the snap feature in the IP4700
volume, and add the following directive before the files to back up in
the class’ file list.
SET SNAPSHOT=T
Be sure to spell “SNAPSHOT” correctly. If NDMP variables are misspelled,
no error message appears, but the backup simply will not run as you expect.
For more information about snap copy, see the IP4700 Administrator’s
Guide.