So a couple of months ago, the company I work for was interested in using a domain controller at a fairly large and important event that we conduct yearly. The idea was that rather than having to do last minute changes on about 120 laptops to accommodate various groups or needs, we could just push out any changes needed via group policy and save oodles of time. To keep things nice and mobile, we decided that a ThinkPad T61 would make an awfully nice mobile domain controller. We even threw in a second SATA drive into a removable tray so that we could have RAID-1 on our mobile DC. And that is when we hit the first snag.
Apparently, Microsoft deems it dangerous to be able to create dynamic disks and/or RAID arrays on laptops due to the “removable” nature of the media. In all fairness, I don’t really blame them – who in their right mind would set up a RAID array using a removable drive on a laptop? Well, that’s exactly what we needed to do. Here’s how we did it:
If you search Microsoft’s website for a few minutes (hint: laptop dynamic disk) you will get a bunch of results, none exactly telling you what you need. If you look a bit closer, you’ll notice this article entitled “Laptop May Incorrectly have Option to Upgrade Basic Disks to Dynamic”. Whoa, wait a second here. The wheels turned in my head for about 5 seconds and then I thought to myself “why not just do the opposite of what this kbase says and purposely break my laptop to get what I want?”. Sure enough the clouds parted and I was able to have my mobile RAID array. It is fully functional and completely reliable – I tested every possible variation of purposefully corrupting data or accidentally ripping out the drive, but the worst that happened was needing to rebuild the array from the surviving disk as intended.
Here’s the resolution text from Microsoft’s website to save you a few seconds. Just do the opposite of what it says to do.
WARNING: If you use Registry Editor incorrectly, you may cause serious problems that may require you to reinstall your operating system. Microsoft cannot guarantee that you can solve problems that result from using Registry Editor incorrectly. Use Registry Editor at your own risk.
To disable the “Upgrade to Dynamic Disk” command, use the following steps.
NOTE: If you have already created any Dynamic disks, delete any volumes on the Dynamic disks and revert them to Basic disks before continuing.
1. Start Registry Editor (Regedt32.exe).
2. Locate the Start value under the following key:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\dmload
3. On the Edit menu, click Modify.
4. Change the data value from 0×0 (boot) to 0×4 (disabled), and then click OK.
5. Quit Registry Editor, and then restart the computer.
