DFSMStvs uses the services of the system logger for logging. Logging captures the data needed for backout. An undo log is private to a unit of recovery. The undo log contains images of changed records as they existed before they were changed. The system logger writes log entries to the coupling facility, data space, DASD, or some combination of the three.

Log records can also be written to a forward recovery log. The forward recovery log contains copies of records after they were changed. The records are written to the system logger log streams. Forward recovery logs are shared between systems; these logs are shared across all CICS® and DFSMStvs instances. This provides sysplex-wide merged log streams that can be used as input to forward recovery products such as CICSVR.