VERITAS Volume Manager 3.5 Administrator's Guide (September 2004)

Administering Cluster Functionality
Dirty Region Logging (DRL) in Cluster Environments
Chapter 10 359
VxVM tracks which nodes have crashed. If multiple node recoveries are
underway in a cluster at a given time, their respective recoveries and
recovery map updates can compete with each other. VxVM tracks
changes in the state of DRL recovery and prevents I/O collisions.
The master node performs volatile tracking of DRL recovery map
updates for each volume, and prevents multiple utilities from changing
the recovery map simultaneously.