An AdvFS fileset clone (see Section 1.7.11) is a read-only snapshot of fileset data at the time the clone was created. The fileset clone tracks the changes to the fileset over the life of the clone. AdvFS fileset clones are analogous to controller-based snapshots. Controller-based clones are similar to LSM split mirrors. Controller-based cloning and snapshotting do not require that the AdvFS file system be installed.
Controller-based cloning and snapshotting are hardware operations. You can use controller-based cloning to create a full duplicate data set on different physical storage media from the original data set. Controller-based snapshotting copies only the critical RAID metadata for a data set to new media. It employs copy-on-write technology to preserve a point-in-time copy of the original data set.
You can mount controller-based clones and snapshots as new AdvFS file systems and use the new file systems in back up operations either on the original host or on a different host. If you mount the new file systems on a different host, you can perform backupswithout introducing a performance drain on the source system during the backup operation. You can also use controller-based clones and snapshots as the data sources for decision-support applications.
Caution
Follow the directions in the Best Practice for Using Controller-Based Cloning and Snapshotting with Tru64 UNIX. Failure to do so may result in unmountable file systems, data corruption, AdvFS domain panics, or Tru64 UNIX kernel panics. See http://www.tru64unix.compaq.com/docs/ for more information.