Applies to: FA-3xx, FA-4xx, FlashArray//M, Windows Server 2008, Windows Server 2012
A Windows 2008 or Windows 2012 Server is rebooted within the environment to apply patches, perform maintenance etc. Once the server successfully boots into Windows the LUNs which are supplied by Pure Storage remain in an "offline" state due to the following reason:
"The disk is offline because of policy set by an administrator".
You are able to bring the drive back into service manually by right clicking the drive and selecting "online". Once the disk is online it is able to service IO as expected and no further issues are noted.
This issue can be seen after a Purity 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 because our LUNs are assigned new 'revision numbers' when an upgrade of Purity 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 because of a design change within Windows 2008 and forward where the default SAN policy for shared drives is set to the following:
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.
The first step to resolving this issue is changing the SAN Policy to "Online All" as per our Windows Configuration: Configuring MPIO & Adding LUNs to Windows Hosts KB. By setting this policy you ensure that any newly created disks attached to the Windows Server will be in an online state after a Windows Server reboot.
This task can be completed by following the Microsoft TechNet Article: https://technet.microsoft.com/en-us/library/gg252636.aspx
If the SAN Policy was set to 'Offline Shared', and disks were already presented to the Windows host from the FlashArray, then you must edit the existing disks 'Attributes' to ensure they will remain online following a Purity upgrade and Windows host reboot. For assistance with this, please contact Pure Storage Support.