APC SCSI-SATA II manual These numbers mean “Free snapshot space” and “Total snapshot space”

These numbers mean “Free snapshot space” and “Total snapshot space”.

4.Choose a UDV by clicking the checkbox of the row and then click

“”.

5.A snapshot UDV is created with the date and time taken snapshot of the chosen UDV. The snapshot UDV size is the same as the chosen UDV no matter the actual snapshot UDV data occupies.

6.Attach LUN to UDV, please refer to section 3.6.6 Logical unit number for more detail.

7.Done. It can be used as a disk.

Figure 4.4.1.1

(Figure 4.4.1.1: No.1 is a RAID 0 UDV. Set snapshot space to 10GB. And now its space is free to snapshot. No.2 is a snap UDV taken on 02/14 17:13:35.)

Snapshot has some constraints as the following:

1.Minimum RAM size of enabling snapshot function is 512MB.

2.For performance concern and future rollback, the system saves snapshot with names in sequences. For example: three snapshots has been taken and named “snap1”(first), “snap2” and “snap3”(last). When deleting “snap2”, both of “snap1” and “snap2” will be deleted because “snap1” are related to “snap2”.

3.For resource concern, the max number of snapshots is 32.

4.If snapshot space is full, controller will send a warning message about space full and the new taken snapshot will replace the oldest snapshot by rotation sequence.

5.Snap UDV cannot be migrated, when doing migration of related VG, snap UDV will fail.

6.Snap UDV cannot be extended.

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