When you have Storage Foundation for Windows (SFW) installed and create or import a cluster dynamic disk group, existing PhysicalDisk resources in your Windows 2008 Failover Cluster (FoC) can be reported as "Failed".
Cluster Administrator shows Physical Disk resources as "Failed"
In rare cases, while preparing the SCSI reservations for the Cluster Dynamic Disk Group, Storage Foundation for Windows 6.0 can reset SCSI reservations on all disks including Basic Disks that are also cluster resources. The reservation for these disks are not renewed, and the PhysicalDisk Resources fail.
This issue is addressed in SFW 6.0 CP2 and later. This is available on SORT via Patch Finder.
SFW with Microsoft Cluster option
Microsoft Failover Cluster