Can I setup a software RAID in Windows 7 using Virtual Hard Disks?

windows-7 raid software-raid virtual-drive

I convert my comment to an answer, as the comment by @C0D3M0NK3Y confirms it.

Windows will not accept dynamic virtual disks in a RAID, but the comment by @C0D3M0NK3Y confirms that fixed-size disks used to work in XP Professional. There is therefore an excellent chance that fixed-size virtual disks will still work with RAID in Windows 7.

It is actually quite logical that Windows cannot create a RAID over dynamic disks whose size is unknown and can change at any moment.

EDIT/ADD:

Had to try it to see either way for sure, and it works (when using fixed-sized VHDs):

Host OS: Windows 7 Ultimate, with two "Basic" disks.

VM OS: Vista Ultimate.

Created two "fixed sized" VHD's of 500MB each, one on each of the host's physical disks, and attached them to the VM (as the 2nd and 3rd drives).

Initialized the new disks in the VM and then converted them to "Dynamic" disks (in Vista's Disk Management).

Then joined them together into a RAID0 (stripe):

Span in a VM

Volume Size

Worked like a charm, without any need to do anything 'weird'.

Author by

user1559100

Updated on September 17, 2022

Comments

user1559100 almost 2 years
I know I need a callback to solve this problem, but I just can't get it right. I've tried a few different solutions, but I'll save you from having to look at my attempts. Instead, I'll just show what I'm trying to accomplish.
```
theCodeToRun('123', '1');
//Wait for it to complete...
theCodeToRun('123', '0');

function theCodeToRun(myID, exitEarly){
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    if(exitEarly == 1){
        return false; //Exit
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    //Do some more stuff
}
```
- Breakthrough almost 13 years
  
  +1, good question. I can see myself possibly using this as well, but you might want to extend the question to allow for alternative disk formats (i.e. not only the VHD format).
- Chris Smith almost 13 years
  
  What I want to know is how Disk Management knows that it is a virtual disk to treat it differently. Getting it to appear as a regular disk would be one way to fix it. +1 I hate stupid limitations like this.
- harrymc almost 13 years
  
  "dynamically expanding" : how about trying fixed-size VHDs ?
- Ƭᴇcʜιᴇ007 almost 13 years
  
  @harrymc - That was one of my questions as well (But I guess I never asked. ;) : Were you using fixed-size VHDs when trying this?
- C0D3M0NK3Y almost 13 years
  
  First let me say I'm not normally a Windows user, however, in Windows XP Professional there was a way to create a fixed size virtual disk and create a software RAID array. I used to join multiple 200GB drives together to have one big 1TB drive appearance in Windows. How to this? I can't remember. I haven't used Windows regularly in over a years.
Ƭᴇcʜιᴇ007 almost 13 years

I'm not sure how CodeMonkey's comments really confirm or deny anything to do with VHD's, as XP doesn't have anything inherent for creating or dealing with VHDs? Did you actually try it (yet)? :)
harrymc almost 13 years

@techie007: I didn't and won't try it, and he probably used a 3rd-party product. But it sounds very logical and so worth trying by the poster. And didn't you yourself just validated my answer? But why did you post it as a separate answer from mine ?
Ƭᴇcʜιᴇ007 almost 13 years

I posted it as a separate answer because it was a tested answer of "Yes it works", vs. "It should logically work, and someone else says it worked for them once in XP" with no info on how they did it. If others agree, I'll happily axe my answer and move the contents into yours (or something). It's not like either of us need the bounty. ;)
harrymc almost 13 years

@techie007: I am happy that my answer has inspired you to verify it for the benefit of the poster and the SU site. I leave any decision in your hands (if you decide to edit mine, you have my blessings).
Ƭᴇcʜιᴇ007 almost 13 years

Well wanting to know the answer myself (from earlier), and the lack of anyone actually verifying it one way or the other is what 'inspired' me. :) I'll pull my gun faster next time. ;)
Denis Nikolaenko almost 13 years

On my Windows 7 Ultimate SP1 I cannot create or convert fixed size VHD to dynamic disk format. The "convert to dynamic disk" menu option is greyed out for the VHD. I tried 2GB in size, if that matters. You cannot get any kind of software RAID without first converting into dynamic disks.
Ƭᴇcʜιᴇ007 almost 13 years

@Dennis That's kind of weird. I can't say for sure what is up with your setup (without knowing more about it). I didn't do anything more than the regular steps. Unfortunately I don't currently have a Windows 7 VM set up.
Denis Nikolaenko almost 13 years

@techie007 I have tried in Windows 7 x64 SP1 VMware Workstation 7 VM with 1GB fixed size .vhd disk. Still greyed out...
Denis Nikolaenko almost 13 years

@techie007 Tried with the same setup but, with x86 VM. Same results. Menu option is greyed out. Tried diskpart utility. Its convert command also fails with "unsupported" error. No dice...
Denis Nikolaenko almost 13 years

@techie007 I have reread your description of the process several times. Blah! Are you attaching .vhd from your virtualization software? So that guest Vista sees them as "real" hard disks?
William Lawn Stewart over 12 years

Fixed size virtual hard disks don't work in Windows 7, unfortunately. It only works inside a VM, not outside.
Steve over 9 years

To improve the storage spaces answer... You don't have to do anything special as far as creating the vhds on separate drives. Simply create all your vhds, then launch storage spaces and bind them together. Then on boot do an automount of all the vhds used by the storage space - then storage space will happily come in to existence again. Works like a charm
Allan Xu over 7 years

I am trying this with Windows 10 storage space and it does not allow me to mirror disks, Has anyone tested this with windows 10 storage space?