How to setup software mirror of boot drive in Win7?

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Nerva

Weaksauce
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Oct 12, 2008
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For some reason I couldn't get this to work on my new Windows 7 install.

My server used to run Windows Home Server 2011, and I had set up a mirrored boot drive using two 60GB SSD's. The boot drive was a dynamic disk with a 100MB boot partition and the rest was the system partition. The mirror was a dynamic disk with an identical partition setup.

I got fed up with WHS 2011 and decided to switch to Windows 7. I wiped one of the 60GB drives and installed W7 -- but this time it created two special partitions instead of one -- I think one was 120MB and the other was 100MB, with the remainder for the system partition -- and it was a basic disk.

This structure apparently messed something up when it came time to set up a mirror. When I attempted to convert the boot drive from basic to dynamic, only the system partition was converted. Also, the 120MB partition is not displayed at all.

I deleted the old partitions from the other 60GB drive and tried to set up the mirror, but the 100MB EFI partition has no actions that can be performed on it. If I try to just mirror the system partition, it gives an error about the partition structure not matching -- and there's little use in mirroring just part of the disk anyway.

I am wondering if there's a way to salvage the situation and set up a mirrored boot drive.
 
I don't think you can do a windows mirror on the bootable drive. You cold do it with hardware raid though, Just be aware it might degrade performance significantly.

Someone feel free to correct me if I am wrong. I'm pretty sure you can't boot off of dynamic disks though.
 
I KNOW I had my WHS2011 boot drive mirrored previously. I don't know why it worked in that situation but not this one...
 
I say its better to have a backup anyways. I mean RAID1 does not count as a backup.
 
Short version: probably more trouble than its worth to fix

It sounds like something has gone wrong with regards to the system reserved partitions. There should only be one, and it should be at the beginning of the disk. Additionally, there should be a tiny slice of unallocated space at the end of the disk, but that doesn't actually show up in disk management. It is required to be there though to convert a disk to dynamic.

You don't convert partitions to dynamic, you convert disks. It's a dynamic disk, not a dynamic volume.

With all of that said, it is almost certainly salvageable, however it's probably more trouble to do so than to wipe the disks and just reinstall Windows again with properly blanked disks. I've managed to fix problems with dynamic disks, but you'll almost certainly need a third party partition tool to do it (like partition magic) because the built-in disk and volume management tools are a bit simplistic for actually fixing problems.

In line with what drescherjm says, can I ask why you want to mirror a 60GB boot drive for a Windows 7 box? With only 60 GB of space, you're almost assuredly not keeping a redundant copy of any of your actual valuable data, as presumably that's on a larger spinning disk drive.
 
The mirror is simply to ensure that if the boot drive fails, I can be back up and running in a short time. Yes, the real data is kept on an array of big drives, and I use Stablebit DrivePool to turn it into a single huge pool, and to duplicate the important data. I also run online backup in case the worst happens.
 
Also, it looks like Partition Magic got killed by Symantec (I HATE that company -- they buy so many companies and shut them down), so there is no version of Partition Magic that runs under Windows 7.
 
Microsoft are paranoid that its mirror function may produce a disk, which if used by someone else, would give them effectively a free copy of Windows. This is why, unlike hardware raid, the MBR and / or boot sector are not present on the mirror. This expressly disables the mirror as serving for a bootable replacement of the original disk. There ways using dd in Unix to copy those missing items, but it may then be necessary to copy the "disk unique id" also if not already done.

If you make a perfect clone of the source disk, using some program like Casper, and then boot your system with both the original and copy online, Windows will sneakily CHANGE the disk unique id so that an error will arise if you attempt to boot from the copy. You can change the disk unique id back to what it was on the original disk, but it is an esoteric extra step that virtually no one knows to do, and even fewer know or can find out HOW to do.

My solution, after making a forensic-quality (perfect as to each bit and its position on the drive) clone, using Casper or the Unix command dd, is to disconnect the copy before rebooting the system. If you wish you can connect these drives one-at-a-time to make sure both will boot, and there will be no trouble with the disk unique id because the drives have not been booted with both online.

But talk about hating Symantec! I think some of us have forgotten since Bill Gates rehabilitated himself through philanthropy, that Microsoft used to be the greatest evil in the computing world, willing to impossibly burden users to assure perfect non-infringement of copyright. What we are discussing here is the descendant of that.

BTW hardware RAID is expressly designed to make your copy bootable, and it is much easier than in Windows software to mirror the boot drive. Just create a RAID 1 pair, and (as I do, though you may not) do a dd copy of the disk I want in an actual effective mirror relationship from the original disk to the new RAID pair.

I get very angry when I see how difficult Microsoft has made easy, convenient backups, even though a cloned disk will probably STILL fail to function in a different machine because of too many hardware differences. You know, they tried to shut Casper down; but of course they can stand on their heads and point Lugers at everyone and still get nowhere against Unix. Thank God.
 
Oh yes, my first computer ran Windows 3.0 and I quickly became a staunch OS/2 fan and MS hater. While Symantec has never had anything like the iron-grip on the industry or stifled innovation the way MS did, what got me hating Symantec was watching them buy one innovative company after another, only to milk their good names. Both Norton and Central Point made excellent DOS and Windows utilities that included backup capabilities. After buying both of them (and simply discontinuing CP's products) they bought the other major DOS/Windows backup company Fastback. I was working in software sales when Windows 95 was about to come out and was talking to the Symantec rep, who confided they had no backup programmers on staff and was negotiating with HP to buy their backup business -- my jaw dropped at the idea that Symantec could have bought all the major backup companies and simply laid off the programmers, only to be left flat-footed when the market changed.
 
P.S. Did you know Easeus Partition Manager is much the same as Partition Magic, but it's free, and works with Windows 7 and 8.
 
Try this:

Attach both hard drives. Boot to 7 install media. When you are at the screen to select your disk, press Shift+F10 to bring up the cmd prompt.

Follow these instructions using Disk Part cmd line.

Back on the disk selection, refresh the view and select the disk.

Because the Dynamic volumes store the raid configuration, Windows will simply detect it's a Mirrored volume regardless of when it was created.
 
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