HP StorageWorks Snapshot XP user guide (T1713-96023, October 2006)

NOTE:
• Contact your HP ac count support representative to install additional shared memory for the V-VOL
management area.
• After installing additional shared memory for the V-VOL management area, you cannot partially
uninstall it. To uninstall additional shared memory for the V-VOL management area, you must
uninstall the entire shared memor y added for the V-VOL management area.
• Skip step 1 if shared memory for the diffe rentialtablesisalreadyinstalled.
• Note that step 2 and step 3 are interchangeable.
• Skip step 3 if Business Copy XP is already installed on the array.
• Since the total capacity of S napshot XP P-VOLs and pools will be considered as the capacity used
by Snapshot XP, you need to purchase enough license for them.
Uninstalling Snapshot XP
1. Delete all Snapshot XP pairs.
2. Delete all pools.
3. Delete all V -VOLs.
4. Uninstall Snapshot XP.
For more information about deleting pairs, pools, a nd V-VOLs, see S napshot XP op e rations.
Calculating the number of Snapshot XP pairs you can create
The number of Snapshot XP pairs you can create for an array depends on the number of differential
tables, V-VOL management area's shared memor y capacity, or number of pair tables. To calculate
the number of Snapshot XP pairs you can create, first use the number of differential tables, then use
the V-VOL management area's shared memory capacit y, and finally use the number of pair tables.
Then compare the three results. The smallest value is the maximum number of Snapshot XP pairs you
can create for the array.
Using the number of differential tables
You c an use a maximum of 13,652 differential tables for an array if additional shared memory is not
installed. You can use a maximum of 30,718 differential tables if additional shared memory is installed.
To calculate the number of Snapshot XP pairs you can create, calculate the number of differential tables
required for the Snapshot XP pair and com pare it with the number of differential tables for the whole
array. In addition to Snapshot XP, the following software products use differential tables in the array:
• Business Copy XP
• ShadowImage for z/OS
• Hitachi FlashCopy Mirroring
• Hitachi FlashCopy Mirroring Version 2
• Flex Copy XP
• Auto L UN XP
If you use any of these software products in the same array, calculate the number of differential tables
Snapshot XP pairs can use by subtracting the number of differential tables the pairs use (migration plan
for Auto LU N XP) for these soft ware products from the number of differential tables for the whole array.
For more information about calculating the number of required differential tables for Business Copy XP,
ShadowImage for z/OS, Hitachi FlashCopy Mirroring, Hitachi FlashCopy Mirroring Version 2, Flex Copy
XP, and Auto LUN XP, see the soft ware product's manual.
To calculate the number of differential tables for each Snapshot XP pair, use the following formula:
24
Requirements for Snapshot XP operations