iSCSI LUNs offline after upgrade to Windows Server 2012

Applies to: Windows Server 2012 DatacenterWindows Server 2012 DatacenterWindows Server 2012 Standard


Consider the following scenario:

  • You have a Windows Server 2008 R2 system configured with iSCSI LUNs.
  • The iSCSI LUNs are not used to boot Windows.
  • The iSCSI LUNs are online.
  • You initiate an upgrade to Windows Server 2012.

In this scenario, when the upgrade completes, the iSCSI LUNs are present but they are offline.


During the upgrade process, the disk information is migrated to the new operating system. The iSCSI initiator service however, is not available at the point where the disks are migrated. As a result, the iSCSI LUNs are not brought online automatically.


After the upgrade is completed, bring the iSCSI LUN online manually. This can be accomplished with the Disk Management utility, DiskPart tool, or with WMI storage commands.