RAID problems

[boofhead]

Dell Studio 540 1 Tb computer. House power failed last weekend (blackout). Power supply was fried and being a Dell I have to get one mail order. It was in a surge protector but obviously not a good one. Meanwhile I took one out of an old computer to see if it would work, and managed to get the thing spinning up and briefly giving me the OS (Vista).
But then it stopped, and the message is that it cannot see any HDDs. I was not aware of this before, but I have found it is not a 1Tb drive but two 640G drives in a RAID setup. I cannot find what type of RAID but I have seen it listed on Ebay as RAID 0. How can I find out what type of RAID it is?
One of the HDDs is labeled HDD 0 while the other is labeled as HDD 1.
Can I setup the RAID again, if it has dropped whatever it needs to run two drives? Can I get my programs and data running again? Is it possible to recover any data if the RAID is out of whack? Would it be RAID 0 or, since the machine is only a couple of years old, a RAID 1 or better?
I have a backup of the data but it is a few months old and I have a lot of movies and pictures that I don't want to lose, but cannot afford to pay for a recovery service either. I used EASUS once to recover some data on a normal HDD and that was a great program, would it work with a RAID setup?
How do I go about restoring the RAID, if such is possible, and can I expect the system to run normally if that is done?
I was told that I could boot to the BIOS and tell it to restore the RAID, but does that destroy any data?
Why didn't I know it was a RAID system? Shouldn't it be disclosed?
Thanks, Dell.

[Mac the Knife]

Unfortunately RAID 0 does not offer any redundancy. The data is "striped" across the drives and the loss of one drive really means the loss of all the data. RAID 0 decreases the access time for data ( greater speed) at the expense of reliability. Reliability is roughly inversely proportional to the number of members – so a set of two disks is half as reliable as a single disk if one fails. Because the data is striped, even partial recovery is difficult and normally incomplete.

EASUS won't help I'm afraid so you are very likely SOL!

Very nasty of them to use RAID 0 and not warn you about it.

Mac

[Mike-Bracknell]

Originally Posted by Mac the Knife

Very nasty of them to use RAID 0 and not warn you about it.

Umm, they don't do this without warning you about it. You make the choice when ordering.

[mixture]

Why didn't I know it was a RAID system? Shouldn't it be disclosed?

There's an old saying in IT..... RTFM, and also in the case of dell, look at what you've spec'd on the website.

Umm, they don't do this without warning you about it. You make the choice when ordering.

Not only that, but it's a lesson learnt the hard way for the purchaser that when something turns up in a box, you take a couple of minutes to check the configuration is as expected and, in the case of RAID recreate the logical drive in the RAID format you require having spent a couple of minutes on Google looking at the pretty diagrams that show you exactly what the difference is between the different RAID types.

Furthermore, it's yet another lesson learnt the hard way that your need to BACKUP AND CHECK YOUR BACKUPS ! This comes up time and time again here on PPRune..... backup backup backup backup, how many times do you lot need to be told !

The MINIMUM rule for backups is that at any one time you should have three copies of your data :
- Live (the one you are using, and yes, RAID is considered "Live", as its only one logical system)
- Nearline Backup (generally an online medium such as external hard drive ...so you could use something like Apple's Timemachine delta snapshotting.... or you could upload to a cloud service if you trust them with your data).
- Offline (i.e. tape or other medium that spends its life disconnected from your machine unless being written to or read from for the purposes of backup/recovery). And no, "the cloud" or a NAS box sitting in a cupboard under the stairs do NOT count as offline. Tape is best, external unplugged hard drive is next, but if you insist on using USB sticks for this, use a minimum of two from different well known brand major manufacturers (copy the same data onto both sticks !!!).

Why is the third offlline disconnected element so important ? Because it gives you protection against live corruption of data, whether accidental or malicous (viruses etc). If you maintain a bunch of offline media of various vintages (or follow a rotation scheme such as GFS, Hanoi or other), it also gives you a greater chance at recovery from creeping corruption scenarios where you don't notice it until it's too late.

You then build upon the minimum above to meet your own requirements (e.g. offsite storage of offline media, rotation schemes in order to build additional redundancy and/or data retention requirements etc.).

RAID is not infallible... believe me, I've seen some pretty nasty data corruption scenarios !

[Mac the Knife]

Provided the disks and controller are not physically trashed you may be able to recover.

Pull the power connectors (NOT the data connectors) of your RAID 0 pair.
Stuff in a new hard drive (not so easy with the Dell) and install your Windows on it.
Make sure your BIOS is set to boot from that drive and make sure you can boot from it reliably.

Go to ReclaiMe Free RAID Recovery software and read everything very carefully.

Download "ReclaiMe Free RAID Recovery" and install.

Powerdown and reconnect the power connectors for your RAID pair.

Reboot and IGNORE Windows offers to format your drives!

Run ReclaiMe Free RAID Recovery and see what you get.

Good luck (I am NOT responsible if you lose the whole lot)

Mac

[Saab Dastard]

Maybe worth a look?

Lots more via google

SD

[boguing]

The only way ahead that I can see is to hook the drives up to a machine with exactly the same raid hardware and software. In other words, get a new psu for the Dell.

As you've been correctly informed, half your data is one one hdd, and half on the other.

For the future you could consider adding another pair of drives in a raid 0/1 array. This gives you speed and backup.

If one drive fails, you can get the software to 'rebuild' the array with no risk of data loss.

That is what I used to do. Worked well until the main board died. Had almost everything backed up, but to get what wasn't, I had to buy a clone board from eBay. Because only the same raid hard/soft will work.

It's also true that raid can still be corrupted. Virus/lightning/sheer bad luck.

I now back up to one of three externals. I have one, daughter has one and son has another. We swap drives whenever we meet.

[green granite]

Can I suggest that before you start messing around you wait until you get the correct PSU for the computer.

[exeng]

Not really a raid type person

My solution - cracking a nut with a sledgehammer perhaps.

A desktop with two 2tb drives - one is a clone of the original drive before any corruption (I use a free acronis). However I also regularly save any important data to the cloned drive.

I also save all data to a third usb independent drive (amongst other drives - I'm scared to death about loosing my Wife's photos)

My first drive has become corrupted once and I recovered it by cloning it back to the original 'cloned disk', complete with all data. Then I just had to update the disk with windows update etc.

Not very clever perhaps but it seems to work for me.


Regards
Exeng

[boofhead]

I have looked at a lot of the stuff you guys and gals have recommended, and await the psu before trying some of it. Thanks a lot for the help to date, and I am sure I will be coming back for more!

[boofhead]

The new psu solved the RAID problem and I can see the drives again. The boot sequence had to be fixed in order to make the PC run with Windows but it is doing so right now. The RAID was an Intel system and worked fine once the power was repaired.
Thanks for the help.

[green granite]

Which was precisely why I said wait for the new psu before fiddling with anything.

[NaKalloy]

just for the record / next time, this program can reconstruct data from a broken RAID0 or RAID5
RAID Reconstructor - Recover Data from a Broken RAID Array

[MacBoero]

I would love to know how useful data recovery from a broken RAID0 set is? If a disk breaks in a RAID0 set, you have definitely lost data and the best you can hope for is partial recovery of some of the files.

[rh200]

If you have a RAID zero and a disk is stuffed, there is no recovery. The data is striped across both drives, or how many drives you have, in my case sometimes 16 or 8. There is no information what so ever on the remaining drives to reconstruct for the failed one.

It is possible depending on the type of failure you could extract the information off the damage drive and clone it onto another, then get your raid back.

[COCL2]

that program is meant for situations where the drives are physically OK but scrambled, or the RAID controller has failed. So all the drives are present, but just not linked