How to Undo RAID: Best Practices

It seemed like a simple, relatively safe task: I needed to undo the RAID array on my PC.

As its primary boot drive, my production system used a RAID 0 array consisting of a pair of Corsair Force GT 240GB drives paired to create a single 480GB volume. All of the valuable data lived on a single 2TB, 7200RPM Western Digital RE drive. The system is based on a Gigabyte GA-X79-UD3 motherboard running a Core i7 3930K CPU. Intel's RapidStore storage software manages the array in Windows.

One day, RapidStore presented me with a "SMART event" notice, indicating that the drive had generated an error from the SMART monitor built into the drive controller. SMART (Self-Monitoring, Analysis and Reporting Technology) constantly monitors the drive for potential failure conditions, and generates an error when it detects such a condition. Unfortunately, SMART rarely provides specifics about the source of the problem; a single SMART event may turn out to be nothing at all, or it may be a crucial harbinger of imminent drive failure.

One of these Force GT drives generated a SMART error.

The first thing I did was fire up Acronis Backup and Restore and made a full backup image of the array. Then I went online to search for a replacement drive. I found a Crucial 512GB M4 SSD for under $400. I had to double-check the price--$399 for 512GB seemed pretty low--but it turned out to be the real deal; even on Crucial's website you can pick up this model for just $412. The drive sports full SATA 6-gbps support, and reviews show it to be a reasonable (albeit not fabulous) performer. Since my main system's input/output needs aren't especially heavy, it sounded perfect, offering slightly more storage and substantially reduced risk. I figured that, after installing the Crucial SSD, I would no longer need to run RAID.

So I ordered one, and waited nervously for a couple of days until the drive arrived.

Clone Wars

My main system is based around an LGA 2011 system, which uses a fairly recent version of Intel's ICH RAID controller. The Acronis software made backing up an image of the boot array in Windows to a secondary drive easy.

I unpacked the Crucial M4, which looked fairly unassuming.

The Crucial M4, 512GB of SSD for well under $1 per gigabyte.

I attached the SSD as a secondary drive and canceled the Windows message that asked me to create a volume after booting up. Then I fired up Acronis Backup and Restore, and launched the process to clone a drive. I cloned the drive "as is" (meaning that all of its partitions would be the same size), having discovered on an earlier occasion that this is the best way to guarantee proper cloning of a boot drive. I also confirmed that options to make the cloned drive bootable and to copy the NT signature were selected.

The system rebooted, and Acronis launched as a pre-Windows boot process and cloned the drive. I then set up the drive in the system BIOS to be the boot drive. After restarting the system, everything booted without any trouble.

Feeling pretty confident now, I detached the two Corsair Force GT drives, but kept RAID mode enabled. I even went so far as to blow away the RAID array, leaving the backup drive image I'd made earlier as my only security blanket.

'Boot Drive Inaccessible'

The system attempted to boot, but didn't like the boot drive, despite having just booted from the same drive a few minutes earlier.

At this point I went through a systematic process of boot-drive troubleshooting:

I checked the BIOS to make sure that either RAID mode or AHCI was enabled. Neither would boot.For the sake of completeness, I tried booting with the BIOS set to IDE mode. Still no boot.I also tried booting from a Windows 7 Setup disk and selecting the system. The following error popped up: "This version of Windows repair is incompatible with the version of Windows installed on this system."

That last error message made no sense, as I was using a Windows Ultimate x64 setup disk to attempt to repair a Windows 7 Ultimate x64 installation.

Finally, I tried booting from my most recent Acronis Backup and Restore boot disk. When I selected the image backup file, however, Acronis asked me for my "credentials"--and my Windows login and password failed. I was stymied.

It was time for coffee and a little thinking.

I returned to my office, fired up a laptop, and searched the Acronis website. I discovered a much more recent version of Backup and Restore 11. The version number--11--was the same, but the actual software revision code had changed. I downloaded the new version and created a new Acronis boot disk.

Holding my breath, I booted the Acronis restore disk. I wasn't asked for a password this time. I checked to make sure the NT signature wasn't cloned, but created fresh. The restore went flawlessly. When I rebooted, I was greeted with a Windows screen. Life was good once again.

There was one more wrinkle, however. My Adobe apps needed to be reactivated, possibly because I'd changed the NT signature on the drive. Everything else--games, Windows itself--didn't require this extra attention. To reactivate the Adobe apps, I had to call the Adobe help line, but that call went smoothly, with no issues or roadblocks.

Lessons Learned

I learned several lessons from this experience. Admittedly, they weren't new lessons, but stuff I've had to relearn repeatedly:

If you're planning to clone a drive, copying the NT signature as-is doesn't always work. Create a fresh one every time.Don't wipe your old boot drive until you're 100 percent sure that your system is booting properly off the new drive.Make sure that you have the latest version of your backup and restore software--particularly if your system is running newer chipsets and storage controllers.

There's still plenty left for me to learn. Setting up and breaking down RAID arrays may seem like child's play, but there's nothing quite like the terror of realizing that you've accidentally destroyed years of private photos, documents, and data during a botched hard drive migration. So play it safe--back up often, and share your PC storage best practices with other readers in the Comments section.

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