Flashes (Alerts)
Abstract
When the RECONCILE VOLUMES command with FIX=YES in run in parallel with backup operations, such as client backups or the BACKUP STGPOOL process, the server can delete data that was recently written to virtual volumes.
Content
WHO IS AFFECTED:
The problem only affects environments that use virtual volumes. This is any configuration with a device class of type SERVER. The problem only occurs if you issue the RECONCILE VOLUMES command with FIX=YES while a backup operation is in progress.
PROBLEM SUMMARY:
When a backup operation runs for a SERVER device class, the data is stored on a target server, and records of that data are maintained on the source server. While the backup operation continues, there is a timing window where the committed records on the source server and the committed volume data on the target server are not synchronized. If the RECONCILE VOLUMES command with FIX=YES is running and evaluates the source records and target volume data during this window, it might attempt to delete data on the target server. In this situation, the following messages are issued when a target archive volume is detected and deleted:
ANR4355W RECONCILE VOLUMES: Volume <volume name> not valid, source server missing
corresponding entry for target server.
ANR4362W RECONCILE VOLUMES: Invalid volume <volume name> deleted from server <target server name>
for device class <device class name>.
This will leave an orphaned entry in the source server's records after the backup operation completes. Thus, if subsequent RECONCILE VOLUMES command with FIX=YES is issued after the completed backup operation, the RECONCILE VOLUMES command will delete the orphaned source records, and the following messages are issued:
ANR4356W RECONCILE VOLUMES: Volume <volume name> not valid, target server missing corresponding
entry for source server.
ANR4363W RECONCILE VOLUMES: Volume <volume name> access changed to Unavailable.
RECOMMENDATION:
Do not attempt to run the RECONCILE VOLUMES command with FIX=YES while a backup operation is running for any SERVER device classes. If a RECONCILE VOLUMES command with FIX=YES is necessary, ensure that all backup operations to SERVER device classes are suspended for the duration of the command.
PROBLEM RESOLUTION:
This problem will be resolved in Tivoli Storage Manager server versions 6.2.6.0, 6.3.5.0, and 7.1.1.0 with APAR IC93989.
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Document Information
Modified date:
25 September 2022
UID
swg21655392