Recovering a RAID-5 Volume

When a member of a mirrored or RAID-5 volume fails, it becomes an orphan. The operating system determines that it can no longer be used and directs reading and writing all new data to the remaining members of the fault-tolerant volume.

When a member of a RAID-5 volume fails, you can reconstruct the data for the failed member from the remaining members. In Disk Management, select a new area of free space that is the same size as or larger than the other members of the RAID-5 volume, and then regenerate the data. If you are required to restart the computer, the volume manager reads the information from the stripes on the other member disks and then reconstructs the data of the missing member and writes it to the new member.

To regenerate a RAID-5 volume, the volume must be locked by the operating system. All network connections to the volume are lost when a volume is regenerated.

Note

Do not put your page file on a RAID-5 volume because it degrades performance. If you want your page file on a fault-tolerant volume, use a mirrored volume instead.

Replacing a Stripe in the RAID-5 Volume

To replace a stripe in the RAID-5 volume, you need a dynamic disk with unallocated space that is at least as large as the stripe to repair. If you don't have a dynamic disk with enough unallocated space, the Repair Volume command is unavailable.

When a member of a RAID-5 volume fails in a severe manner (such as a loss of power or a hard disk failure), it becomes an orphan. If this happens, you can regenerate the data for the orphaned member from the remaining members of the RAID-5 volume.

If the RAID-5 failure is due to a power or cabling failure on a single device, you can regenerate the data within the orphaned member of the RAID-5 volume once the hardware state is restored.

Note

The RAID-5 volume does not display the Healthy status in Disk Management until regeneration is complete.

Deleting a RAID-5 Volume on a Basic Disk

Deleting a RAID-5 volume deletes all the data contained in the volume as well as the partitions that make up the RAID-5 volume. You can delete only entire RAID-5 volumes.

Note

In Windows NT 4.0 and earlier, RAID-5 volumes were known as stripe sets with parity. Disk Management renames all stripe sets with parity to RAID-5 Volumes. In Windows 2000, you can delete RAID-5 volumes that were created in Windows NT 4.0 or earlier, but you cannot create RAID-5 volumes on basic disks.

Repairing a RAID-5 Volume on a Basic Disk

If a basic disk containing part of a RAID-5 volume is disconnected or fails, its status becomes Failed Redundancy and the disk status remains Online. If this happens, you can try to repair the volume. The RAID-5 status of the volume should change to Regenerating and then Healthy.

When you repair a RAID-5 volume on a basic disk, Disk Management relocates part of the RAID-5 volume to a healthy disk, regenerates the parity, and then returns the status to Healthy.

Repairing a RAID-5 volume on a basic disk requires an additional basic disk with sufficient free space for part of the RAID-5 volume. If an additional disk is not available, the Repair Volume option is not available and you cannot repair the volume. If the disk containing part of the RAID-5 volume cannot be reactivated and the volume does not return to the Healthy status, replace the failed stripe in the RAID-5 volume.

Note

You must use a basic disk to repair a basic RAID-5 volume: you cannot use a dynamic disk.

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