Tape Backup Recommendations - Hitachi AMS2100 User Manual

Tape backup recommendations

Hitachi AMS 2000 Family Copy-on-Write SnapShot User Guide
Securing a tape-backup of your V-VOLs is recommended because it
allows for restoration of the P-VOL in the event of pair failure (and
thus, an invalid V-VOL). This section outlines a general scenario for
backing up two V-VOLs:
• A P-VOL is copied to two V-VOLs everyday at 12 midnight and 12
noon.
• Tape backups of the two V-VOLs are made when few I/O
instructions are issued by a host. Generally, host I/O should be
less than 100 IOPS.
• Backup to tape should use two ports simultaneously.
• The total capacity of each V-VOL must be 1.5 TB or smaller.
When the total capacity is 1 TB, time required for backing up (at
a speed of 100 MB/sec) is 3 hours.
• Data pool capacity should be increased to 1.5-times the capacity
of the P-VOL. This is because all the data that is restored from
tape to the V-VOL becomes differential data in relation to the P-
VOL. Therefore, the data pool should be as large or larger than
this. It is recommended that the data pool be sized to 1.5 times
the P-VOL capacity as a safety precaution.
Figure 6-1 illustrates this example scenario.
Using SnapShot
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