RAID-5 Volumes

RAID 5 Volumes are similar to striped volumes. However, as well as striping the information across 3 disks it also creates parity information, which can be used to recover lost data in the event of a disk failure. Therefore this system is fault-tolerant.

You can use anywhere between 3-32 disks in a RAID-5 set. RAID-5 Volumes are only supported by Windows Server 2003 not XP.

If one disk fails, its data can be regenerated from the compressed parity information and the remaining data from the other drives in the set.

In a RAID-5 set, read speed is increased but write speed is decreased due to the generation of the parity information. Space is used less efficiently than a single drive as the equivalent of one disk in the array is needed for parity information.

To create a RAID-5 volume using Disks 0,1 and 2, Right-click on the Unallocated space on Disk 0.

Select New Volume.

The New Volume Wizard will appear. Click on Next to continue.

Select the type of volume to be created, in this case RAID-5.

Click on Next to continue.

Disk 0 has already been added. To change the size of the volume, specify the size in MB into the amount of disk space box.

The size of the volume has been changed to 2048MB. To add Disk 1 to the RAID-5 set highlight Disk 1.

Click on Add.

Disk 1 has been added to the RAID-5 set, notice that 2048MB of space has also been taken from Disk 1. Click on Add to add Disk 2.

All partitions in a RAID-5 set have to be the same size. Space equivalent to one of the partitions will be used for the parity information, making the total size 4096MB. Click on Next to continue.

This RAID-5 volume will be assigned the drive letter E:. Click on Next to continue.

The drive will be formatted with NTFS. Click on Next to continue.

The summary page will appear, click on Finish to create the new volume.

The new volume is displayed and is spread across three physical disks, notice the fault tolerance and overhead settings

The volume appears as a single drive in My Computer.

If one the drives fails as shown below, the RAID-5 volume will remain intact.

..and will still be accessible as before, if slightly slower due to the rebuilding of the original data from the parity and remaining data.