TC initial copy activities can impact the performance of the primary site, depending on the amount of I/O activity and the number of pairs being created at the same time. The maximum initial copy activities option allows you to specify the maximum number of concurrent initial copy operations that the storage system can perform. For example, when the maximum initial copy activities is set to 64 and you add 65 TC pairs at the same time, the primary system starts the first 64 pairs and will not start the 65th pair until one of the first 64 pairs is synchronized.
You can also enable or disable the CU option for the maximum initial copy activities setting. If the CU option is enabled, you can specify the maximum concurrent initial copy operations for each CU (range = 1-16, default = 4), and if it is disabled, you cannot specify the setting separately for each CU. If the CU option is enabled and you set a value larger than the system setting for maximum initial copy activities for a CU, the system setting for maximum initial copy activities is observed.
The default maximum initial copy activities setting is 64 volumes. You can set a number from 1 to 512. If the maximum initial copy activities setting is too large, pending processes in the secondary site can increase, and this can impact the remote I/O response time to the update I/Os. You can change this setting using the Edit Remote Replica Options window. For instructions, see Setting the remote replication options.