Backup, MFC and other multi-threaded operations may crash if conflict with reclaim
The multi-threaded scan operations, introduced in versions 3.0 and 3.1,
do not coordinate correctly with reclaim, and may cause the multi-threaded
operation to crash with a page header fault, SEGV, or other error.
The multi-threaded operations that are affected are:
- backup (3.1 and later)
- objectAudit
- markForCollection
- findDisconnectedObjects
- countInstances*, listInstances*, listReferences*, listObjectsIn*, findObjectsLargerThan*
- GsObjectInventory
Normally, if a reclaimed page is encountered during one of these operations,
the operation will terminate. There is a very small chance that a page
could be reclaimed, and reused as another data page, in such a way that
the backup would not detect that it was changed, which may result in missing
objects from a backup.
Workaround
Customers should disable reclaim GcGems before running any of the multi-threaded
operations, and reenable after the operations completes. To disable/reenabled,
you may execute the following:
System stopAllReclaimGcSessions.
System startAllReclaimGcSessions.
Last updated: 9/11/13