RAID Failure, But Drives OK. Best Way To Rebuild?

[SYSMAN_MK]

Right need some ideas. Came in this morning to find machines not being able to print. Tracked it down to an issue with SYSVOL not replicating, AD an everything else was operating fine. Made some changes and rebooted the server. Then got greeted with the message that RAID Mirror that holds the OS had 2 failed drives!

Now thing is the RAID Bios is reporting that 2 drives are 2 simple RAID volumes that have both failed rather than 1 mirrored volume. I have removed both drives and stuck them in a caddy and it would seem that both drives have all the data intact. Files that were copied to the drive before the restart are on both drives so it would seem like the mirror was working.

So my question is going to be the best way to rebuild the array? Server is the first DC and is an HP ML110 G5

Cheers in advance

[nephilim]

Clone the HDDs with new (similar) HDDs and try that? It could be the RAID Card is not reading the drives and new ones will be needed. I have come across that before

[Michael]

This is a little tricky. So you're using a RAID1 array for the OS?

You could contact HP and see what they suggest. If you've no support agreement, I would probably install one existing drive and one new drive (as you normally would) and see if it'll replicate. If it does, (once complete) install a second new drive and replicate to that.

Alternatively you could install two new drives, re-create the array, install Windows Server as normal, name the server as before, and then perform a full system restore, including the system state.

[Michael]

In saying that though, I'm guessing the server will not boot into Windows as it reports both drives as 'failed'?

Replicating back to a new drive probably isn't an option. You could clone one disk as mentioned above, or install as new and restore from a backup. The problem with cloning the drive is that you might be cloning duff information if there is a fault with one or both drives.

At least if you took a backup yesterday or the day before, everything was working correctly then with no SYSVOL errors.

[SYSMAN_MK]

Yes was a RAID1 Mirror for the OS With all the HDDs connected the RIAD Utility sees 1 Mirror Volume ( Data) and 2 simple RAID volumes (the 2 drives from the OS mirror) Now the RAID utility states that both Simple RAID volumes have failed. So at this point in time the drives have the data intact but no RAID info.

Now I'm thinking of trying to add 1 drive and create a new array with it, but will this destroy the current data? Another option would be to fit 2 new drives, create the new array and then like you say restore from backup. But along those lines would it be possible to image one of the drives to the array?

[Michael]

Although it's a longer job, I probably would create a new RAID1 array and restore from a backup. Creating the new array may not even work, which would mean you have a duff RAID controller.

If you can re-create a new RAID1 array, then I would perform a full restore. It should work absolutely fine then.

[SYNACK]

First up, take a backup/image then you have a couple of options. Either wipe both drives, recreate the mirror then dump the image back on.

Option 2, wipe only one of the drives and put the other one back in then boot the server. Reboot the server with the second, wiped drive in it and go into the RAID console then set the mirror to write it back to the wiped drive. This option will be quickest and you can probably do most of it with the server online and running the restore in the background.

[SYSMAN_MK]

Thing is the console doesn't see the old mirror, just 2 simple volumes.

[SYNACK]

Thing is the console doesn't see the old mirror, just 2 simple volumes.

Yeap, you'd create a new volume with the left alone one as the source and the freshly wiped one as the destination when you create the mirror. It does depend on the RAID controller but I think the 110 one does this. You should even be able to do it without wipeing one of the disks but it may be safer to do the wipe for error checking etc.

[SYSMAN_MK]

Right I have disconnected the working data mirror and one of the OS mirror drives. Booted into the RAID Utility and set the the Simple volume as boolable and restarted and the server has booted into the OS! Now to set up a mirror.