Recommended Cache capacity with Universal Volume Manager
If you are using Universal Volume Manager, 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 volumes.
Transfer speed is not important.
Cache mode of the mapped volume is Disable.
The CLPR uses only volumes for open systems.
The following table lists the recommended cache when the total external volume capacity with Universal Volume Manager is equal to or more than or less than 128,000 GB.
|
Total capacity of external volume of CLPR with UVM |
Number of MP units |
Recommended cache capacity for a CLPR |
|---|---|---|
|
Less than 128 TB |
4 |
4 GB |
|
128 TB or more |
4 |
8 GB |
When adding cache memory, use either the Standard Cache Access Model mode or the High Performance Cache Access Model mode. If the storage system has any additional printed circuit boards (PCBs), you must use the High Performance Cache Access Model mode. For more information about adding cache memory, contact the Hitachi Data Systems customer support.