Unable to create software RAID volume in unallocated space on primary disk

I have two disks that I'd like to partially combine into a striped volume (RAID0). Disk 1 contains the primary partition that boots into Windows 7 Professional, disk 2 is currently not used. On disk 1, I have 20 GB of unallocated space, and disk 2 has roughly 110 GB of unallocated space.

My understanding is that I should be able to create a RAID0 volume using the 20GB of unallocated space on disk 1, and 20 GB of the unallocated space on disk 2.

Unfortunately, the Windows disk management tool only allows me to create a "New Simple Volume" on the unallocated space of disk 1, whereas on disk 2 I have the whole range of options at my disposal.

Why is that?

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(I've attached a screenshot that's actually two screenshots merged together, showing both menus. I apologize for the Dutch language, but it should be fairly obvious what the available options represent.)

redburn

Posted 2013-07-11T13:47:38.230

Reputation: 365

Answers

You can not create software RAIDs on basic disks. It looks like your OS is in German (Guten Tag!) so it seems to be called "Standard" for you. Check out this article on Basic and Dynamic disks. You will need to convert your disks to dynamic before you can do RAID.

Keltari

Posted 2013-07-11T13:47:38.230

Reputation: 57 019

And by converting the primary disk from basic to dynamic, I lose the ability to boot from that disk? Or so the disk manager tells me. That's a bit of a dealbreaker. It's Dutch, by the way ;) – redburn – 2013-07-11T14:02:02.807

Dutch/German, its all Greek to me – Keltari – 2013-07-11T14:08:00.330

It doesn't explain why it is possible to opt to create RAID volumes on the second disk, which, like the first disk, is a "Standard" disk rather than a "Dynamic" one. – redburn – 2013-07-11T14:19:43.660

because there is no volume. It would convert it to a dynamic disk, since nothing would be lost. – Keltari – 2013-07-11T14:30:22.897

That makes sense. I found another disk that I can use instead of the one with the boot partition, and indeed upon creating the striped volume I was asked if the disks could be converted to dynamic ones. That was the key to understanding my problem, so I'll now mark this as answered. Thanks! – redburn – 2013-07-11T14:35:13.723

Even though this is possible afaik, it would be a bad idea as the read heads of disk 0 would alternate between the raid0 partition and the primary partition, greatly reducing disk performance. Doing this would also mean that if either of the disks failed you would lose all of the data in the raid.

I would recommend expanding the primary partition of disk0 into the empty 20GB and creating a new non-raid partition on the other disk.

Anon

Posted 2013-07-11T13:47:38.230

Reputation: 28

You raise a good point, though these are SSDs so I'm not too worried, and my motivations are primarily of an experimental nature. – redburn – 2013-07-11T14:10:07.277