Raid Hard Disk Problem

  [DELETED] 01:24 24 Feb 2006

I have two hard disks 1 80GB Maxtor and a 40GB Seagate These have been set up on a raid array (I Think type 2)But the 80 GB drive has literally stopped working. It was working fine when I turned my PC off when I turnesd it back on an hour or two later it was stone dead. No go whatso ever. since this was the master drive of the array the PC would not boot and neither could I enter the BIOS to find out what was going on, it just crashes at the detection screen. If disconnect the 80 GB drive or connect the 40gb on its own I get a message saying that "no array can be detected" the boot continues and I can now enter the BIOS, But of course cannot access any drive. Is there any way of retrieving my data. (beside spending £600 on a retrieval company). I have considered buying a new 80gb Maxtor and swapping the platters in the hope that it will last long enough to copy the data onto a new larger disc. Do I have any chance of succeding with this plan? I have practiced taking an old disk apart and realise that keeping it clean and undamaged would be a challange to say the least but this would be cheaper than a data recovery service. Also is there a way of getting the data from the 40 gb disc onto another disc (I can set up a new bigger disc on an EIDE port). Any help would be appreciated.

  [DELETED] 03:56 24 Feb 2006

Taking a HD apart is gonna kill it unless you happen to have a laboratory under the stairs,as tiny moisture droplets from your breath will eat into the platters surfaces like acid.Dust will cause data corruption,and if you look in Speakers Corner there is a link to a video of the HD heads which is truly amazing the speeds it travels about.

  [DELETED] 21:06 24 Feb 2006

Whatyou say makes excellent logical sense. But I'm still tempted it only has to work long enough to get most of the data off. I have access to to masks overalls etc (I work in Pharma industry could probably con myself the use of a clean room if I tried hard)itll save £650 if I succeed in getting the data off, and if I fail I'm not much worse off cos there is no way I'm spending that kind of money on reteiving the data. I'll ponder it a bit. In the meantime any ideas how I can retrieve the data on the slave 40GB Raid disk which is working OK.
Thanks for your help.

Cheers Slydog

  [DELETED] 21:41 24 Feb 2006

If the original set up was raid 1 (mirror) just put another hard drive in equal or larger in size and rebuild the array from within the RAID setup in the BIOS.

  Big Elf 22:26 24 Feb 2006

I'm just curious. You seem to know something about PC's but don't appear to have a backup routine for what seems like important data.

PC Bilbo's suggestion might (just) work providing you had a mirrored rather than striped RAID configuration and also providing that the other disk hasn't developed problems.

Why didn't you backup to other media (hard drive/DVD etc.?)

  [DELETED] 23:36 24 Feb 2006

With two hard disks the array can only be RAID0 (striped) or RAID1 (mirrored). If yours was RAID0 then your data is spread over both disks and recovering it would be an extremely difficult job even for a professional firm.

If it was a RAID1 array, then there is a chance that you might be able to retrieve the data without too much difficulty. As Big Elf says, only if both disks in the array are faulty is there a problem in recovering the situation. That's the virtue of this configuration - each disk has a complete and identical copy of your operating system and data. Note also that neither is the 'master' disk - just that the system is set to boot from one or the other.

You don't say which RAID diagnostic tools you have on your computer. I get a message on booting to press F10 to enter the RAID manager, which gives information on the state of each disk. Once in, there is also a utility nvRaid, which enables the boot disk to be switched from one to the other. Both of these should work even if one disk is kaput, and the solution then is simply to replace the dead disk with a substitute preferably identical to the working disk and then rebuild the array.

In your case, with the 80Gb disk removed from the system, you say that the system eventually boots from the 40Gb disk but you have no 'access to any drive'. But clearly that drive is there and working, and it's a question of detecting and reading it. What operating system are you running, and what does it tell you about the other components of your system?

  [DELETED] 09:53 25 Feb 2006

Thanks for your respones
In answer to big elf yep your right I do Know a bit about PC's but as they say familiarity breeds contempt and I was always going to back it up tomorrow.
Uncle P Yep Im pretty sure it was raid 0 therefore striped.I seem to remember going for the higher disc space option when I set it up (several years ago now)Raid was pretty new then and it seemed like a good idea. Also discs are not same size as I think they need to be for a mirrored array. However neither disc boots into operating system at all. Iv'e tried setting both discs to master/slave,on their own on the system and linked together and I either get an array not detected message. At which point I can enter the BIOS which shows neither disk have been detected. Or it boots up to array detection screen (which is pre windows load)and stalls. In this configuration I cant enter the BIOS at all.
Looks like I'm goosed then!

  [DELETED] 17:15 25 Feb 2006

My commiserations - I was very sorry to read your reply.

My limited experience is with RAID1 systems. About two years ago, the single disk on my old computer failed; although I had backed up data files etc, it still took the best part of two weeks to rebuild a similar configuration on a new disk - time I could ill afford. When I bought a new machine last year, the cost of a second hard disk to provide some security against disk failure was pretty marginal. Although the RAID1 system initially appeared attractive, I'm not sure that it's better overall than using a second disk, whether internal or external, to store images of the master disk contents.

The problem with RAID0 is that it isn't really a genuine RAID configuration - there's no redundancy present. The way the data is striped across the two disks means that you need to be able to read both to recover anything at all, not to mention some fancy software to weave together the fragments. This also probably explains why you can't see either disk separately.

  [DELETED] 18:38 25 Feb 2006

Hey Ho we live and we learn. Thanks for your help anyway.
Cheers slydog

This thread is now locked and can not be replied to.

Elsewhere on IDG sites

Microsoft Surface Book 2 15in review

Illustrator Amy Grimes on how setting up her own eco-brand led to success with clients too

MacBook Pro keyboard issues and other problems

Test : l’enceinte connectée HomePod d’Apple