Veritas Volume Manager supports the following types of volume logs and maps:
FastResync Maps are used to perform quick and efficient resynchronization of mirrors. These maps are supported either in memory (Non-Persistent FastResync), or on disk as part of a DCO volume (Persistent FastResync).
Dirty Region Logs allow the fast recovery of mirrored volumes after a system crash. These logs are supported either as DRL log plexes, or as part of a version 20 DCO volume.
RAID-5 logs are used to prevent corruption of data during recovery of RAID-5 volumes. These logs are configured as plexes on disks other than those that are used for the columns of the RAID-5 volume.