Hard Drive failed

[nicdan]

Hello, We fired up our computer last night and it looks like one of our hard drives might of died. We have 4 Seagate Cheetah drive stripped together to make 72GB. How can we figure out which one went? Or could it be all 4? Not sure how to separte the drives. If only one went can we recover data that might of been lost? Hopefully this makes sense to you and that I worded it correctly. I appreciate any help you can give.

Thanks!
Michelle

 

[wahnula]

Michelle,

What is the size of each drive? It should be on the label of the drive. What is the drive scheme, like RAID 1, RAID 5, RAID 1+0 etc.?

You should be able to get this information at POST, if the drives are striped into an array there will be a key-combo choice like "Press CTRL+L to enter RAID (or SCSI) BIOS" which will tell you the configuration of the array, the member disks, and which one (if any) is not working.

Chances of recovery are good if it's not a RAID 0 array. The more details you can offer about the PC will increase your chances of getting a good answer.

Tony

Users helping Users...

 

[BadBigBen]

how are they stripped together? RAID 0, RAID 1 etc...

with RAID 0, you may be out of luck when you replace a drive, as these 4 drives are connected to form ONE continuous array...

with RAID 1, you replace the drive and hope that you can rebuild the RAID without data loss...

maybe others have more information for you, than I do...

PS: it would be helpful to know the sizes of these drives, ergo the description that is written on them, sound like SCSI and the Cheetah brand had many sizes...

Ben

"If it works don't fix it! If it doesn't use a sledgehammer..."

 

[PRPhx]

By any chance, does your RAID controller have any management software????? This will tell you which drive(s) is/are bad.

I know many people don't like RAID 5 or 6, but in this situation, it's ideal for replacing a bad drive. With a descent RAID controller, you simply swap out the bad drive with a new one, and let the controller rebuild the array.

 

[nicdan]

Thanks guys for your response's. I went to turn it back on to try to get some information and my video drives did not show failed anymore and I was able yo continue my work. I shut down the computer last night, and than fired it back up tonight and now it says failed again??? I am confused why it's doing this.

Any idea's?

Thanks!
Michelle

 

[BadBigBen]

That is a sure sign that it is a.) failing, so grab the DATA off of it when you get access again, or b.) that the cable is either loose or damaged...

but you still haven't answered any of our questions...!

Ben

"If it works don't fix it! If it doesn't use a sledgehammer..."

 

[nicdan]

Thanks Ben! I know I am sorry about noe answer the questions. I thought that maybe the computer was just acting up and felt better. Any who....I will get that info and post it. I am not good at this tech stuff, so I will do the best I can.

Thanks
Michelle

 

[wahnula]

Michelle,

When trying to remotely solve a problem there is some information that we really need, a week later we're still clueless about your PC. What we need (minimum):

* Make, model, brand, number, relative age and typical usage of the PC;
* Hard Drives: Make, model, size, type (PATA vs. SATA vs. SCSI vs. SAS) I know this sounds daunting but I use Google Images to get a visual confirmation;
* Other stuff: Optical drives, PCI add-in cards, RAM (size & type), anything & everything about what's inside your PC.


Tony

Users helping Users...

 

[nicdan]

Okay, here is the information. It's Raid 0. The size of each drive is 72GB. Its a Cheetah SCSI. 10,000RPM.

The one drive that says failed in the disk managemant. Can we delete that drive and still use the other 3 even if they are stripped together?

Thanks again!!
Michelle

 

[nicdan]

Tony,
Here is some information for you. I hope it is what you are looking for.

Computer system: Microsoft Windows XP Professional 2002
Service pack 2
55274-OEM-0048531-30110
Computer: Intel XEON (tm) CPU 2.00GHZ
1.98 GHZ
1.00 GB of Ram

Hard Disk drives:

System (c)37.2GB
Audio (D) 18.6 GB
F_X (F) 18.6 GB
Video 2 (s) 136Gb

Seagate Cheetah SCSI everything is about 5 years old and is used for editing video only.

Any other infor that is missing please tell me where I can locate it for you.

Thanks again!
Michelle

 

[wahnula]

This is the way it appears to be set up to me:

(2) drives striped in RAID 1 for C:, D:, & F:
(2) drives striped in RAID 0 for S:

So, if my assessment is correct, the PC should boot up, you should be able to access Audio & F_X, just not Video2. Is this correct?

Tony

Users helping Users...

 

[BadBigBen]

Michelle, thanks for the info, as I stated earlier, RAID 0 you will have loss of data...

RAID 0 failure rate

Although RAID 0 was not specified in the original RAID paper, an idealized implementation of RAID 0 would split I/O operations into equal-sized blocks and spread them evenly across two disks. RAID 0 implementations with more than two disks are also possible, though the group reliability decreases with member size.

Reliability of a given RAID 0 set is equal to the average reliability of each disk divided by the number of disks in the set:

That is, reliability (as measured by mean time to failure (MTTF) or mean time between failures (MTBF) is roughly inversely proportional to the number of members — so a set of two disks is roughly half as reliable as a single disk. In other words, the probability of a failure is roughly proportional to the number of members. If there were a probability of 5% that the disk would fail within three years, in a two disk array, that probability would be upped to Pr(at least one fails) = 1 - Pr(neither fails) = 1 - (1 - 0.05)^2 = 0.0975 = 9.75\,\%.

The reason for this is that the file system is distributed across all disks. When a drive fails the file system cannot cope with such a large loss of data and coherency since the data is "striped" across all drives (the data cannot be recovered without the missing disk). Data can be recovered using special tools (see data recovery), however, this data will be incomplete and most likely corrupt, and recovery of drive data is very costly and not guaranteed.

Source: Wikipedia (Standard RAID levels) see also: RAID

http://en.wikipedia.org/wiki/RAID

you may get lucky and be able to get 3/4 of the data from the rest of the drives by using a DATA RECOVERY software... Whanula (Tony) may have more info on recovering data from RAID 0 arrays, than I do... (I have never used RAID 0)... but I would start by just replacing the CABLE with a new one, that way it is out of the equation and unplug the power to the drives (all of them) and then replug them several times, in case it is corrosion that caused the drive to fail...

was there any Backup strategy?

suggestion for the future, use RAID 5 for important DATA and use a backup strategy!



Ben

"If it works don't fix it! If it doesn't use a sledgehammer..."