When a node leaves a cluster, the new membership is delivered by GAB, to CVM on existing cluster nodes. The fencing driver (VXFEN) ensures that split-brain scenarios are taken care of before CVM is notified. CVM then initiates recovery of mirrors of shared volumes that might have been in an inconsistent state following the exit of the node.

For database files, when ODM is enabled with SmartSync option, Oracle Resilvering handles recovery of mirrored volumes. For non-database files, this recovery is optimized using Dirty Region Logging (DRL). The DRL is a map stored in a special purpose VxVM sub-disk and attached as an additional plex to the mirrored volume. When a DRL subdisk is created for a shared volume, the length of the sub-disk is automatically evaluated so as to cater to the number of cluster nodes. If the shared volume has Fast Mirror Resync (FlashSnap) enabled, the DCO (Data Change Object) log volume created automatically has DRL embedded in it. In the absence of DRL or DCO, CVM does a full mirror resynchronization.