After 2008R2 starts I see constant disk activity on disks that are in a RAID 5 group, this occurs whether the volume is basic or dynamic, formatted or unformatted, or offline & uninitialized. In diagnosing this situation I've used the same disks in RAID 1 &/or RAID 0 groups and gone so far as to initialize the volumes in Windows and I don't see disk activity on those disks. Only when the disks are in RAID 5 configuration. The disks are new Seagate ST31500341AS disks the SASMF8i controller is new Ver A.62 Apr 29, 2009 / M1068e.09.06171059I in an intel MB (that does not have an EFI shell which appears to be required to update the SASMF8i firmware if necessary). I've loaded the latest driver v13.16.0308.2010. Any ideas on what's causing this and how to stop the disk activity?