Changes

Whilst RAID 5 has considerable advantages over RAID 0 there are one or two drawbacks that should be taken into consideration when considering this storage option. Firstly, there is the inevitable performance overhead inherent in calculating and storing parity information for each data stripe written to disk. Secondly, the loss of more than own one disk in a RAID 5 array will leave insufficient parity data on the remaining disks to regenerate the original data. That said, RAID 5 does provide considerable advantages that generally outweigh the disadvantages.

A Windows Server 2008 RAID 5 configuration may be set up using the Disk Management snap-in. This is accessed either from the Server Manager or Computer Management tools. To launch the Server Manager, open the Start menu and click on the Server Manager option, or click on the Server Manager icon in the task bar. Alternatively launch Computer Management from Start -> All Programs -> Administration Tools -> Computer Management or run '''compmgmt.csc''' at the command prompt or in a Run dialog. In all cases the Disk Management tool canbe can be found under the ''Storage'' category.

As previously noted, RAID 5 implementation requires a minimum of 3 disk drives. For the purposes of this tutorial a system containing four disk drives is assumed. In this scenario, disk 0 is the system disk and disks 1 though through 3 are available for use in the RAID 5 configuration. Before proceeding the disks will need to be initialized using either the MBR or GPT partition style. Assuming these prerequisites are met the first step is to right click on one of the 3 disks in the Disk Management graphical view. In the resulting popup menu select the ''New RAID-5 Volume...'' option to invoke the ''New RAID-5 Volume'' wizard. On the wizard's welcome page click on the ''Next'' button to proceed to the ''Disk Selection'' screen. This screen contains a list of disk drives available for inclusion in the disk array together with a list of selected disks. Currently only the current disk is included in the ''Selected'' list. Two more disks must be added to the selected disks before the RAID 5 array can be built. Select disks from the ''Available'' list and click on the ''Add>'' button to add the disk to the selected list. Once sufficient disks (in this case disks 1, 2 and 3) are selected the ''Next'' button will activate to allow the remainder of the configuration to be completed. Note that disk 0 (the system disk) is not included in the RAID 5 array:

In addition to configuring RAID 5 from within Disk Management, the configuration may also be implemented from the command prompt using '''DiskPart'''. DiskPart may be launched either from a command prompt or a Run dialog simply by typing ''diskpart''. Once invoked, DiskPart will display the ''DiskPart>'' command prompt and is ready to receive commands.

For the purposes of this chapter disks 1, 2 and 3 will be used to create a RAID 5 configuration. Each of these disks need needs to be converted to dynamic disks before the configuration can proceed. This is achieved by selecting each disk in turn and executing the ''convert dynamic'' command: