What the snapmirror resync command does

After the snapmirror break command, you apply the snapmirror resync command to either the original SnapMirror destination or the original source.

• Applied to the original destination—the snapmirror resync command will put a volume or qtree back into a SnapMirror relationship and resynchronize its contents with the source without repeating the initial transfer.
• Applied to the source volume—the snapmirror resync command can turn the source volume into a copy of the original destination volume. In this way, the roles of source and destination can be reversed.

• Resynchronizing a SnapMirror relationship
  You can use the snapmirror resync command to restore or redefine a SnapMirror source or destination relationship that was broken with the snapmirror break command.
• How the snapmirror resync command helps minimize data loss
  The snapmirror resync command enables you to reestablish a broken SnapMirror relationship without a lengthy baseline transfer.
• Testing database applications: A special use for snapmirror resync
  Testing software applications that run on a database can sometimes change or even corrupt the database. To ensure that you do not lose data while testing such software applications, you can copy the data to another volume for testing purposes, break the destination volume to return it to writable state, and run the test application on it. Upon completion of the test, you can resynchronize the source and the destination volume to restore the data and repeat the testing as often as you need.
• Retrieving data for disaster recovery: A special use for snapmirror resync
  When disaster disables the source of a SnapMirror relationship, you can use the snapmirror resync command as part of a strategy to update the repaired source and reestablish the original configuration of the storage systems.