RAID problem - corrupted JPEG files

[221B]

I have 2 identical hard drives attached to an Adaptec 1200A raid controller as a raid1 (mirrored) array. Yesterday it decided that it needed to resync the disks, and after a few hours processing declared itself happy.

However now I cannot open any of the files - they are generally JPEGs from a digital camera, and come up with various error messages depending on the application used to try and open them, suggesting that they have becom corrupted.

A google search has not turned up anything, and I am awaiting a response from Adaptec Technical Support - but wondered if anyone on this forum had any insight. I think that the information is still there, but am not sure if it needs to be repaired at the Raid level, or at the JPEG file level - and I am wary of making a recoverable situation unrecoverable.

Thanks in advance.

[All Ahead Full]

This could be nasty - but first thing to do - is back up what you have have.

Then run a goto a command prompt - and run 'chkdsk /f' without the quotes, it will say something about requiring full access to the disks - and would you like to schedule a chck on next re-boot - say yes, and re-boot the unit.

On the next boot - it will run a check disk on the drives, and this may restore the data to a readable point.

The other thing you 'could try' - but with care (hence backing everything up first_ - is powering down the PC, and disconnecting one of the drives - try each one alternatively, to see if that enables you seeing the files.

Let me know

[Liar's Poker]

Do you have any files that you can easily verify as ok (plaintext files)? It seems strange that only jpegs were corrupted. Good luck though, sounds nasty.

Bit late to say backup isn't it? :{

[rustle]

What changed to make it think it needed a "resync"? Not normal as RAID1 is realtime mirroring :confused:

Have you got any other compressed files you can check? (Anything [win]zipped that you can have a look at)

[221B]

Thanks for the tips

"Bit late to say backup isn't it?" - this was the point of putting RAID in place. Mirroring seemed an appropriate solution for around 50Gb of data. Unfortunately it would probably have been alright if I hadn't....

Not sure why it decided to resync - I deliberately steered clear of the other RAID configurations as mirroring seemed the safest bet.

I use the drive to archive digital photos - so there are only JPEG files on the drive. I will check for any other file types that may have found their way onto the drives and see what state they are in though.

My though was to try and disconnect each drive to see if one individually had good files on it. If Adaptec cannot come up with any suggestions I will try the check disk option first. Another option is to force the array to resync again - but I am wary of making the situation even worse.

Will post again with any progress.

[IO540]

RAID would protect only from a HD failure, not from a failure higher up the chain as any corrupted data will get written to *both* drives and you are stuffed.

Since the vast majority of data loss cases are either the user doing something, or a program misbehaving, a backup is far more useful than RAID.

An Adaptec controller should be OK but I have found that the IDE-RAID or SATA-RAID controllers found on a lot of motherboards are lousy. I lost everything a few months ago when one drive in a mirrored pair failed, and now I don't bother with RAID.

The problem is that backing up is very expensive. One needs a tape drive - after all these years there still isn't a better solution for the amount of data one can have an a HD.

[Mac the Knife]

"The problem is that backing up is very expensive. One needs a tape drive - after all these years there still isn't a better solution for the amount of data one can have an a HD."

Oh come on now!

50 quid will get you at least 120GB of decent ATA drive and another few quid will get you a removable drive bracket so you can take the backup drive out and store it somewhere safe.

Yes, I used to use tape, but hard drives are so cheap these days that it isn't worth the hassle.

Ever tried respooling a despooled tape? The chances of your spare HDD going Tango Uniform are a lot less than that!

And as for using mirrored drives for data safety.......ROTFL!

[221B]

The Adaptec solution was to turn off the mirroring and look at both drives individually. Both had the same corrupted data, as might be expected - so at least the RAID was working!

A bit more of a look round and a trawl through the event log showed that a checkdisk had run and 'fixed' a lot of indexing errors. The timing is consistent with this triggering the RAID resync, so now I think that RAID is a red herring and the real problem is the checkdisk, or a corruption that triggered it. I have sent the checkdisk log to Microsoft for suggestions to reverse the process and restore the data.

Some of the JPEG files have blocks of random pixels in the middle, which suggests that the file allocation table (or NTFS equivalent) is the problem, therefore, hopefully the file data fragments are still on the disk. Thanks to the mirroring it looks like I will have 2 chances - my feeling is to find a software package to try myself, and if that fails to find a service I can send the other disk to.

I would welcome recommendations in case Microsoft are unable to offer a solution - I am in the UK and the disk is NTFS format on Windows XP PRo SP2.

Thanks for the replies so far.

[Evo]

I would welcome recommendations in case Microsoft are unable to offer a solution - I am in the UK and the disk is NTFS format on Windows XP PRo SP2.


I must admit that I don't have a great deal of faith in Microsoft's consumer-level support. As for alternatives, I've never used them, but it might be worth talking to http://www.tdrs.co.uk/