States for physical disks (pdisks)

The valid states for pdisks are Active, RWProtected, Failed, Missing, and Unknown.

Active
The disk is functioning correctly.
RWProtected
The disk is unavailable because of a hardware or a configuration problem.
Failed
The controller cannot communicate with the disk, or the pdisk is the cause of the disk array being in a Degraded state.
Missing
The disk was previously connected to the controller but is no longer detected.
Unknown
The state of the disk could not be determined.