This issue can be seen after a Purity//FA upgrade has been performed on the FlashArray sometime since the last reboot was completed on the Windows Host.
The reason the disks are in an offline state is that our volumes are assigned new 'revision numbers' when an upgrade of Purity//FA is performed. The Windows 2008 and Windows 2012 servers then interpret these as "new" disks because of this new revision number and then sets the drives to offline after a host reboot.
The primary reason this happens is a design change within Windows 2008 and forward where the default SAN policy for shared drives is set to the following:
VDS_SP_OFFLINE_SHARED
This means if a new shared drive is presented to a Windows Host it will keep the drive offline to ensure that drive should be presented to this host. If that drive is supposed to be presented to the specific host, then it can be brought online as needed by the Administrator.