- When Universal Replicator is used, if 35% or higher WP rate continues for a long time at the secondary site, a journal usage might exceed the threshold and a UR pair might be suspended due to failure at the primary site.
- In a 3DC configuration, if 35% or higher WP rate continues for a long time at the second secondary site, a journal usage might exceed the threshold and a UR pair might be suspended due to failure at the primary site and the first secondary site. In case of failure suspension, even if delta resync is performed, all data on a P-VOL is copied to an S-VOL in the same way as when delta resync cannot be performed.
- Make sure to disable Inflow Control for journals. The background copy processing is stopped, the amount of host I/Os exceeds the amount of journal transfer, and the journal usage increases. If Inflow Control is enabled, the failure suspension can be prevented, but Inflow Control works when the journal usage exceeds the threshold (80%), resulting in degradation of host write I/O performance.
- When a CCI consistency group consisting of multiple storage systems is used in UR, even if the WP rate is 35% or higher on one secondary storage system in the UR system consists of multiple storage systems, the background copy processing is stopped on all storage systems in the system. Note that the background copy processing is also stopped on the storage system to which SOM 1254 or SOM 1260 is not applied.
- When UR is used, if operations are switched to the secondary site, as the previous primary site becomes the secondary site, make sure to match the setting of SOM 1254 between the primary and secondary sites.
- In a 3DC configuration, make sure to match the setting of SOM 1254 among the primary, first secondary, and second secondary sites because the operations are performed at the primary site, and they might be switched to the first secondary site, and then to the second secondary site.