Dell PowerStore Importing External Storage to PowerStore Guide

Consistency group handling

PowerStore import supports import of Consistency Groups (CGs) from the source systems. At a CG level, either the import succeeds for all the volumes in the CG or, if any volume fails, the import fails for all of them. However, in rare situations, it is possible that the rollback fails for one of the volumes. In those situations, CGs end up in a clean-up required state. This cleanup of the CG must be done after resolving any faults, such as network issues, and then import can be attempted again. Depending on the fault, a manual host-side recovery may be required.

In extreme cases, such as a source SP reboot or source shutdown around the commit window, it is possible that some volumes are committed and some are not. For such rare cases, the source CG must be split, and the individual volumes imported. After import, the volumes can be added to a PowerStore volume group.