Chapter 13: Solving Problems ● 137Failed Disk Drive Not Protected by a Hot SpareWhen a logical drive is not protected by a hot spare, if a disk drive in that logical drive fails,remove and replace the failed disk drive. The controller detects the new disk drive and beginsto rebuild the logical drive.For instance, when one of the disk drives fails in the RAID 1 logical drive shown in the nextexample, the logical drive is not automatically rebuilt. The failed disk drive must be removedand replaced before the logical drive can be rebuilt.If the controller fails to rebuild the logical drive, check that the cables, disk drives, andcontrollers are properly installed and connected. Then, if necessary, follow the instructions inRebuilding Logical Drives on page 138.Failure in Multiple Logical Drives SimultaneouslyIf there’s a disk drive failure in more than one logical drive at the same time (one failure perlogical drive), and the logical drives have hot spares protecting them, the controller rebuilds thelogical drives with these limitations:● A hot spare must be of equal or greater size than the failed disk drive it’s replacing.● Failed disk drives are replaced with hot spares in the order in which they failed. (Thelogical drive that includes the disk drive that failed first is rebuilt first, assuming anappropriate hot spare is available—see the previous bullet.)If there are more disk drive failures than hot spares, see Failed Disk Drive Not Protected by a HotSpare on page 137.If copyback is enabled, data is moved back to its original location once the controller detectsthat the failed drive has been replaced. See Enabling Copyback on page 90 for moreinformation.Disk Drive Failure in a RAID 0 Logical DriveBecause RAID 0 volumes do not include redundancy, if a disk drive fails in a RAID 0 logicaldrive, the data can’t be recovered.Correct the cause of the failure or replace the failed disk drives. Then, restore your data (ifavailable).
