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I have two hard-drives mirrored (i.e. RAID-1)to be my D: volume (non-boot drive) in Windows 7.

enter image description here Click to enlarge.

This is the first time I have tried mirroring in Windows 7, but I've had (sometimes traumatic) experience with Vista and Intel Matrix Storage console.

I expected I could shut down the computer, remove either drive (to simulate a drive failure), and start up the machine again. I expected it to boot normally, with the D: volume working, but warn me that a drive had failed, so I can replace it with a new one.

Instead, when I look at the Storage Management, one drive is marked as missing, and BOTH drives are marked as failed. The D: volume is not present.

What do I need to do to ensure the volume will still be available in the event of a single drive failure?

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Can you explain how the 2 drives are setup/recognised Before the system? back in the bios or any intel bios? anything back at the lower levels of recognition. –  Psycogeek Mar 6 '12 at 20:10
    
@Psychogeek: That question would require quite a reboot (and a camera) to answer, so I don't have that info yet. It is all pretty straightforward though. The two relevant drives plug straight into the RAID-supporting motherboard (ASUS P8Z68-V Pro/Gen3) using SATA II. (The C: drive is an SSD and does likewise). –  Oddthinking Mar 7 '12 at 0:20
    
Because the problem seems like odd behaviour , I was wondering how the drives are setup initially, before it got to the system. There are so many possible ways with something like Intel matrix capabilities. –  Psycogeek Mar 7 '12 at 8:41

1 Answer 1

Well, I was wrong. It is not odd behaviour at all :-)

My research on the web indicates that the system will fail miserably. If you were booting from it, if might not even boot.

In the case of failure, the mirror has to be "broken" (i.e. undo the RAID configuration) or "fixed" (i.e. a second drive installed to replace the missing on.)

When a member of a mirrored volume is orphaned, you need to break the mirrored volume to expose the remaining volume as a separate volume. The remaining member of the mirrored volume receives the drive letter that was assigned to the complete mirrored volume. The orphaned volume receives the next available drive letter or a new letter assigned to it.

I think fundamentally that I need to break the mirror

Normally, if a disk in your RAID array fails, you should be able to shut down the server, remove the failing drive, and replace it with an identical (at least in capacity) drive, and start back up, whereupon the system's RAID controller should begin rebuilding itself.

You had problems before with the hardware-based RAID. Well, everything has its advantages and disadvantages. For my uses, OS-dependence is worse than hardware dependence, but it would depend.

My web research also keeps me away from using "dynamic" disks. They have advantages and disadvantages also. Too many users reported slow-downs. I assume it is somehow due to the redundancy (safety) it has, and the way it stores that redundancy.

Manual mirroring, then disabling the disk device itself might be one way to keep a data disk more secure, in the event of viruses. RAID-1 is for quick recovery during a hardware failure, but mirroring error and damage and deletion makes it less useful for all other soft and user problems. A (device) disabled backup with 90% of the data on it, might still have 90% of the data on it, if a virus wipes out everything.

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Psycogeek: Thank you very much for your response. Some parts of the answer are not relevant to my problem. You describe a mechanism for protecting against viruses and user problems. That is a separate problem. RAID-1 is NOT the same as a back-up (let alone an off-site backup). I am not using it for that purpose. I am using it to protect against a single-point of hardware failure. –  Oddthinking Mar 7 '12 at 12:44
    
The third link describes someone who is having a similar problem to me on Windows 2003, but offers no solution. I am not using an Intel-based solution (I was explaining I have in the past which is where I got my expectations of a automatic fail-over.) –  Oddthinking Mar 7 '12 at 12:47
    
The Technet article is interesting, but seems to support my expectations. "A mirrored volume is provides fault tolerance by duplicating data on two disks. If one disk fails, the data on the failed disk becomes unavailable, but the system continues to operate using the unaffected disk." <- This isn't happening! "If a basic disk containing part of a mirrored volume is disconnected or fails, the status of the mirrored volume becomes Failed Redundancy and the disk status remains Online" <- This isn't happening! –  Oddthinking Mar 7 '12 at 12:49
    
@Oddthinking I was expecting to find some people who had the problem and solved it without undoing the mirror, as we both know it should work. it should complain a bit and go on. Some of the info is too old, but each one (and some others that were not as good) started creating a pattern like you describe , and a solution that is a sad workaround. –  Psycogeek Mar 7 '12 at 13:56
    
The info in the first link, is in the comments. everything working fine on paper :-) then the people who tried it, and actually had to USE it. Nobody lost data, they might lose boot. Also note the comment about ACHI , the excessive rebuild. –  Psycogeek Mar 7 '12 at 14:21

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