The copy threshold option for capacity saving (SOM 1254) 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 virtual volumes with capacity saving enabled.
When this option is set to ON, it can be used to slow down copy processing performed in the background when the cache write pending rate of the MP unit to which the target volume belongs is 35% or higher. Slowing down copy processing performed in the background prevents the cache 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.
For more information about the copy threshold option and the workflow, see the copy threshold option topic in the Provisioning Guide of your storage system.