To prevent the host server's I/O performance (response) from degrading for data reduction shared volumes (DRS-VOLs), use the copy threshold option for the capacity reduction feature.
The copy threshold option for the capacity saving feature has two system option modes (SOMs):
- SOM 1254: Use this SOM when you want to apply uniform functionality to all CLPRs in the storage system.
- SOM 1260: Use this SOM when you want to change the application of functions in CLPR units.
- SOM 1254
- Use SOM 1254 for the capacity saving feature when you want to apply the feature uniformly to all CLPRs in the storage system. If you want to apply different functions to each destination CLPR, use SOM 1260.
SOM 1254 allows you to choose whether or not to suppress the copy operation that runs in the background when the write pending rate of MP units in the CLPR of the destination volume is 35% or higher.
- ON: When the write pending rate of MP units of CLPR on the destination volume is 35% or more, the operation of the copy that runs in the background is suppressed, and the increase in the write pending rate of the destination storage system is suppressed.
- OFF: Follows the setting of the copy threshold option (SOM 467).
- SOM 1260
- Use SOM 1260 for the capacity saving function when you want to apply the function differently for each CLPR of the copy destination. If you want to apply a uniform feature to all CLPRs in the storage system, use SOM 1254.
SOM 1260 allows you to choose whether or not to suppress the copy operation that runs in the background when the write pending rate of MP units in the CLPR of the destination volume is 35% or higher.
- ON: When the write pending rate of MP units of CLPR on the destination volume is 35% or more, the operation of the copy that runs in the background is suppressed, and the increase in the write pending rate of the destination storage system is suppressed.
- OFF: Follows the setting of the copy threshold option (SOM 467).