Creating BWO backups

When you use the Backup-While-Open (BWO) feature, RUV can create a backup of a VSAM file while the file remains open to CICS. The following sections describe how to create BWO backups.

A BWO backup is also known as a fuzzy backup. In contrast with a crisp backup, which is taken while the VSAM file is closed to all processes other than the backup process, a fuzzy backup is taken while the VSAM file remains open to transaction updates. A fuzzy backup is combined with relevant records of transaction updates during file recovery. For more information about crisp and fuzzy backups, see Types-of-backups-needed-for-a-recovery.

In format and structure, a BWO backup is identical to an RUV backup. You use the same JCL to create a BWO backup as you would use to create an RUV backup. The difference is in the backup registration record; if the BWO feature is active and enabled, and if the VSAM file is open to CICS, RUV registers the backup as a BWO backup rather than an RUV backup. This registration information notifies RUV that transaction updates might need to be reapplied at restore or recovery time.