If a Volume is Degraded
A degraded volume is either not providing full performance or has lost its ability to
guarantee data protection. All data on a degraded volume is available, but data will be
lost if a disk fails. A volume’s status is listed as degraded:
 While the volume is being created. This is normal, and the volume’s status changes
from degraded to good as soon as initialization is finished.
 When a disk fails in the RAID 1, RAID 5, or RAID 0+1 set that the volume is based on.
The volume remains in a degraded state until you replace the faulty drive or until an
available spare is integrated into the RAID set.
 While the RAID set that the volume is based on is recovering from a loss of data
redundancy. The volume’s status changes from degraded to good as soon as the
recovery process in finished.