Symantec Backup Exec 2012–Disk Storage Offline

After upgrading from Symantec Backup 2010 R3 to Symantec Backup 2012, I have been facing with the issue of Backup Disk Storage going offline daily.  The Backup Disk Storage is created on an iSCSI LUN with MPIO.  Although the Backup Disk Storage went offline in Symantec Backup Exec, it is still accessible by Windows.

I opened a case with Symantec support and after some troubleshooting and analysis, my issue is related to http://www.symantec.com/business/support/index?page=content&id=TECH189831.  The Disk Storage did go offline when Backup Exec Database Maintenance is completed.

Symantec support provided me a orphan fix which replaces the pvlsvr.exe and StorArMgmt.dll files.  After applying the orphan fix, the Disk Storage has been stable and did not go offline after the Backup Exec Database Maintenance.  I am advised not to apply any hotfixes to prevent overwriting of the pvlsvr.exe and StorArMgmt.dll files until the fix is publicly available.