Performing inline upgrade of Windows Server 2008 R2 into 2012 R2 effects on LUNs ?

[Server-Support]

People,

I'm about to perform OS upgrade of my current backup up server from Windows Server 2008 R2 SP1 into Windows Server 2012 R2 while minimizing the OS reconfiguration and its running application.

I have some NTFS LUNs presented by HP EVA 6300 storage array that is used as multiple drive letters to contains the multiple server backup repository ~ 10TB for each drives (4 of them).

As above screenshot

So do I need to disconnect the SCSI cable behind the HBA during the upgrade or shall I just perform the OS upgrade as it is now without worrying too much about the SCSI HBA driver ?