HP XP7 Storage - Manual (Page 12)

Recommended cache capacity for
a CLPR Number of MP blades Internal/external VOL for a CLPR (Total capacity)
60 GB 14
68 GB 16
64 GB 2 360 TB or more
64 GB 4
64 GB 6
64 GB 8
64 GB 10
64 GB 12
64 GB 14
68 GB 16
72 GB 2 600 TB or more
72 GB 4
72 GB 6
72 GB 8
72 GB 10
72 GB 12
72 GB 14
72 GB 16
Cache capacity with Cache Residency
When you use the Priority mode by using Cache Residency for a CLPR, you may want to add
cache capacity depending on the number of areas in which the priority mode is set in addition to
the cache used for Cache Residency. For more information, see the Priority mode (read data in
cache) section of the XP7 Performance for Open and Mainframe Systems User Guide.
Cache capacity with Compatible XRC
Compatible XRC uses a sidefile that contains administrative information. To allow for the sidefile,
you have to allocate more cache capacity than the value listed in the reference tables. You need
to know the sleep wait threshold to calculate the minimum required cache capacity value.
Use this formula to calculate the recommended CLPR capacity:
Recommended cache capacity = (Recommended cache capacity from
reference tables) × 100 / (100 - (Sleep wait threshold))
Cache capacity with External Storage
If you are using only External Storage, sometimes you can allocate less cache capacity to a CLPR.
To use less cache capacity, the CLPR that you want to create must meet the following conditions:
•
The CLPR uses only external open-systems volumes.
•
Transfer speed is not important.
•
Cache mode of the mapped volume is disabled.
12 Cache Partition operations