# Fix for broken RAID 1 mirror? (Clintfan?)



## patwestlake (Jul 7, 2004)

Hi,

history: 

P4C800E-dlx
ICH5R - 2 x maxtor 80gb SATA - RAID 0 (Operating system)
Promise 378 - 2 x seagtae 120gb SATA - RAID 1 (Data)

Last night one of the seagates gave up  , and in the subsequent reboot whilst I diagnosed just what was going on, the mirror went "offline". I have identified the defunct HDD, and Promise reports the other as holding a healthy array (Array1). I guess that it is waiting for a replacement drive to image to. In the meantime is there any way to de-raid the drive (NTFS formatted) so that I can back the contents up before totally rebuilding the mirror when the new HDD arrives? I assume that the capacity is not an issue as each was a copy of the other. I can't find any info anywhare (asus or otherwise) on this subject....

Any offers?

Cheers, Pat


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## clintfan (Sep 4, 2003)

Sorry I'm not sure, but here are some rambling thoughts...

First, I am surprised that it is not letting you run your RAID1 array "broken". I thought that was the whole idea of RAID1... that you can continue to operate while you get a replacement. Maybe it doesn't really work that way, but instead prevents you from using your good drive until you can replace your bad one? Seems weird to me. I don't fully understand the situation. But good to know, since I run a Promise RAID1 array here for data storage.

AFAIK if you delete a RAID1 array, the two drives become two independent drives. Once this is done, it should be a small matter to make a RAID1 array again using the good drive and a replacement. I think this is pretty standard across RAID controllers. But I really don't know this for a fact.

But if you break the array, don't think you will be able to switch the BIOS to run in IDE mode and boot right up with a single drive, because the OS on the good disk has the Promise _RAID_ driver on it, not the IDE driver. You'd encounter a chicken-and-egg situation: can't boot unless you break the array and install the IDE driver, but can't install the driver unless you can boot!

_Whatever_ you do at this point other than just replacing the bad drive, probably carries some risk. 

Since they're SATA drives, one idea is that you might be able to run your good drive over on the Intel SATA1 port instead... that wouldn't require any special drivers, you could leave your Promise BIOS and driver as-is. I don't know if it would actually work or not: it might require fixing the master boot record (FIXMBR?), or editing the boot.ini, both being tasks I've not had to do yet. At the worst it would not be bootable. Like I said, there's some risk whichever way you go.

I think the proper plan might be,

1. Delete the Promise array in the CTRL+F utility. I think it would be a mistake to move the drive off the Promise and run it without logically deleting the array first. (See risk statement below)
2. Leave your Promise BIOS configured as it is.
3. Replug your good SATA drive to the Intel SATA1 port.
4. Boot the BIOS and make sure the Main- IDE Configuration is set correctly (Enhanced- SATA- RAID-No-35). Readjust your BIOS Boot Device Priority to make it CD-Floppy-3M (hard drive). F10 to save.
5. Try to boot the OS. It will probably "discover" new h/w devices and want to reboot again.
6. If boot works, make your backup.
7. When you get your new drive, move your drive back to Promise and readjust your Boot Device Priority to make it CD-Floppy-FT_Ary1).
8. Use CTRL+F to create a new RAID1 array using your good OS disk as the source drive for the copy.


I think most of the risk is in Step 1, because we assume the data will remain after the logcal deletion. And there is a little risk in Step 5, because we don't know if we will need to fixup some boot stuff to make it work. 

Sorry I don't have any better ideas. 

-clintfan


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## Harry (Sep 25, 2003)

I am running RAID 1 on the Promise controller. I'm curious about your failure. What was the indication that you had a drive failure? Did you get the replacement drive installed? Did you have to do anything to rebuild the array? Anything else of interest?

Thanks, just looking forward to the day when I have a drive failure.


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## patwestlake (Jul 7, 2004)

*Gradually getting data back!!*

Hi Harry / Clintfan

As the dodgy raid array was the raid_1 setup (on the promise), i didn't have any boot or system issues. The message from the promise controller was that the array had failed and that one of the disks was now declared "free" in the fasttrack setup utility. The other contained the array (ARRAY 1) but was offline with no way of recovering it in the absence of a replacement drive. I deleted the array from the drive and rebooted.

So here's where the recovery lessons begin!!

In Raid_1, both drives carry matching drive details (partition info, drive letters etc) so windows throws the dummy out as it cannot now enumerate the drive configs (2 e:\ drives, 2 f:\ drives etc). I have the extra luxury (for security) in that these "data" drives are in removable caddies, so all i did was to remove a drive and reboot with 1 drive (the supposed good drive) installed.

Now you get the promise controller finding only one disk, but doesn't load the raid driver as it ain't raided anymore. System boots, and windows now says that the promise interface has no driver.... So, download and install the TX2plus driver for the promise website and reboot again. Now all the data and partions are visible as assigned to the original raid_1 drive letters. Backup begins!!

Now here's the strange part.... If I reboot with the supposed "failed" drive, i get the same result - ie windows can see it. Change the caddies over, and both drives are individually visible. Ie, neither drive has failed as seen in explorer.... However, the failure itself was manifesting itself in tha the drive would stop reading and freezing the mouse for 5 seconds during data reads. This would repeat every 30 secs or so until the data transfer was complete. This activity has not changed for either drive since de-raiding, so I am currently trying to find the cause (It ain't a virus as i reloaded XP Pro in the interim and have triple checkd all known hijacks, CWS etc. If it is viral, it only afftect the promise controller as the OS on RAID 0 in the ICH5R is spot on..... )

Also disk doctor has found some bad sectors, and i cannot get at some data on the drives. Transfer is also a very long affair as the system freezes every 10 seconds or so for 5 seconds. Once i've got what I need, i'll FDisk both drives and see what happens (will post back)

In the mean time, I guess the story is that you can get at data from a broken Raid 1 array. However, until I sort out what has happened to these two drives , I am of the opinion that RAID 1 does not offer the secure data storage that I was hoping for. I will not be putting either these or replacemnt discs back into the array, and will instead use scheduled backups to do the job i had hoped raid_1 would do. I may yet be proven wrong, but raid 1 for the home PC is over hyped!

Hope some of this rant helps someone!!

Pat


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## Harry (Sep 25, 2003)

Thanks for the report.

How did you get the indication of drive failure? Did you get a pop up telling you which drive failed? I suppose that at that stage you could have pulled the drive that indicated bad, replaced it with a new drive and the array would have rebuilt? I agree it is worrisome that both drives show some signs of problems. I suspect that you are correct that RAID is not a cure all for home PC's.

Please keep us informed of your progress.


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