Veritas Volume Manager supports the following types of volume logs and maps:
FastResync Maps improve performance and reduce I/O during mirror resynchronization. These maps can be either in memory (Non-Persistent) or on disk (Persistent) as part of a DCO volume.
Dirty Region Logs let you quickly recover mirrored volumes after a system crash. These logs can be either DRL log plexes, or part of a version 20 DCO volume.
RAID-5 logs 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.