The copy threshold option for capacity saving enables you to choose whether to slow down copy processing performed in the background when the workload on the storage system is high. By using the copy threshold option for capacity saving, you can prevent the decline in the host server I/O performances (responses) for DRS-VOLs.
When this option is set to ON, it can be used to slow down copy processing performed in the background when the write pending rate of the MP unit in the CLPR to which the target volume belongs is 35% or higher. Slowing down copy processing performed in the background prevents the write pending rate of the target storage system from increasing.
When this option is set to OFF, the copy threshold option (SOM 467) is in effect.
You can use one of two SOMs to enable the copy threshold option for capacity saving, depending on whether you want to enable the function to all of the CLPRs on the storage system or enable the function to individual CLPRs on the storage system.
- SOM 1254
- Use this mode to enable the copy threshold option for capacity saving to all CLPRs on the storage system.
- SOM 1260
- Use this mode to enable the copy threshold option for capacity saving to an individual CLPR on the storage system.
For more information about the copy threshold option and the workflow, see the copy threshold option topic in the Provisioning Guide and SOM 1254 or SOM 1260 in the System Administrator Guide.