Configuring SW RAID on Windows

In the earlier article we saw how hardware configured RAID 0 disk arrays gave performance improvements over single drives.

But to do that you require either a PCI RAID card or RAID support built on your motherboard. In this article we will look at how to configure RAID 0 on your machine without using any hardware controller. For this, you will require two hard drives and Win 2000/XP/2003 installed .

Open the Computer Management console from Administrative Tools in Control Panel. Go to the Disk Management Snap-in. From there, select any disk and right-click on it and select Convert to Dynamic Disk. A small window opens which lets you select all disks that you want to convert to dynamic disks. Select both disks and click OK. Another window gives you the status of your drives and lists the various partitions on it. Click on the convert button. A message box will open up to warn you and will ask for permission to continue.

Some precautions before you proceed to say yes to the warning. Once you have converted your disk to a dynamic disk, you cannot boot any other installed operating system from any partition on that disk. So do this only if you are sure you do not have any other OS to boot from that disk. Also a dynamic disk can be converted back to a basic disk only after all the partitions on it have been deleted. So if you convert the disk, which contains the boot partition of your windows system, to a dynamic disk then you cannot convert it back to a basic disk, as you cannot delete the boot partition. But if you don’t have any other OS to boot from the disk, converting to a dynamic disk is absolutely safe and it works perfectly fine.

After giving a thought to all the above statements, press yes to the warning. The disk manger will then dismount any mounted partitions and may even require a reboot before completing the process of converting all your disks to dynamic disk.

Once the disks have been converted to dynamic disks, the rules of the game change a little bit. First of all the partitions are not called partitions, they are called volumes. Second, you can format these volumes only with the NTFS file system and not with FAT32, though your existing FAT32 partitions will remain as such. Third, now you don’t have primary, secondary or logical partitions but you have simple, spanned and stripped volumes. A simple volume is made of free space on a single dynamic disk. You can extend this volume by adding free space to it from the same disk or another disk. Once a volume is made up of disk space on more than one disk, it becomes a spanned volume. A striped volume stores data in stripes of two or more dynamic disks. It gives faster access to data than simple and spanned volume as data read and writes are done simultaneously on more than one disk, similar to RAID 0, but done by the OS and not by any dedicated hardware.

Let’s see how to make a striped volume. Right click on unallocated space on any disk and select New Volume. The New Volume wizard opens up. Select striped volume. On the next screen select all the disks you want the volume to be striped to.

You will require a minimum of two disks to create the striped volume. Now give the disk space you want to allocate on each disk, all disks have to allocate the same amount of disk space. Suppose you give 5GB space on one disk, the same will also be set for the second disk and the total volume size will be 5+5=10GB. Click on next and assign a drive letter, then next format the partition with the only option of NTFS and finish. You have your RAID 0 volume created using just two disks and your operating system. Our tests confirm better performance for a striped volume than a normal volume.

Anoop Mangla