Windows Soft RAID 1 Experiences

I've been using this feature at work for a few years, and these are some experiences.

So far, we haven't had any disk failures, so it's been fine, mostly.

Setting it up is a little anxiety-inducing. You need to make a regular disk image backup, first, for sure. Also have the installation DVD or a USB key around and a product key. This is essential.

Your second disk is probably going to be larger than the first. This is okay. Just accept the lost capacity. You can replace your first disk, later, and do an expansion. Expanding is a multi-step process, but once you have the RAID 1 in there, and a backup, you're going to have three copies of your data at all times. It's much safer than the usual upgrade.

Overall speed will decline. Writes will be a little slower.

Also, if you ever need to power-cycle the computer, you're going to be hating life for the minutes or hours it'll take for the two disks to re-synch. During resynch, the disk performance is much worse than usual. That's just how it goes. Maybe the odds of file corruption are reduced. You can hope.

Testing the functionality is pretty easy, and you should do it before re-deploying the computer, when you have not only the two synced copies, but the backup disk image on the external disk. All you do is power down, unplug one disk, and see if you can boot to Windows. That should cause Windows to "put the array into a degraded state" (RAID lingo meaning that the fact that a disk failed is noted, so the RAID software can begin recovery or expect that you'll be installing a new disk).

If that works, great. Shut down, re-install the disk, and start the computer. Open the disk manager, and you should see the disks being rebuilt. If that's not happening, it'll ask you if you want to install this "new" disk, you can re-build the mirror with this "new" disk. BTW - use a sticker to label your disks so you don't make a stupid mistake :)

RAID 0 is evil - it doubles your risk of losing data. Don't use it. If you must use RAID0 for performance, do a RAID 10, a striped set that's built on top of mirrored disks.

RAID 5 is troubled - your risk of failure is greater than RAID 1. Spend the extra money to get one more disk and have two RAID 1 arrays. If you must economize and you need a lot of storage, look at RAID 6.