Under certain special conditions of the operating system (e.g. during CPU reconfiguration) the operating system is halted for a certain time. To prevent the risk of erroneous failure detection by MSFC, the system component responsible for the special condition can reserve the Cluster Recovery Lock (CRL) during the critical period. While the CRL is reserved, a fail reconfiguration by MSCF is started after confirmation by systems support.
Current users of the CRL are the VM2000 command MOVE-VM and the live migration. SNAPSHOT does not use the CRL, but has its own connection to disk monitoring.
Normally, the CRL is released after the special conditions have finished. If this does not happen (e.g. because of an error), automatic error handling would be blocked. In this case, the CRL can be released manually with the RELEASE-CLUSTER-RECOVERY-LOCK command (see "RELEASE-CLUSTER-RECOVERY-LOCK" (Release the Cluster Recovery Lock (CRL) manually)).