Raid 0 failing, any way to backup individual hdd?

Silencing hard drives, optical drives and other storage devices

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Raid 0 failing, any way to backup individual hdd?

Post by hapveg » Mon Dec 17, 2007 11:53 am

My question first, then the background information:
Is it possible to copy the data from a failing drive onto a spare drive, and replace it in a raid 0 without any problems?

Possibly relevant background:
One of the hard drives in my raid 0 is failing, it sometimes wont start up properly, and randomly has very loud seeks.

The first thing I did was backup my important data to another drive, but now I'm wondering if there is a way to fix this problem.

The raid 0 is 4*160gb Samsung Spinpoint (Nidec motor) SATA drives, I have a spare drive (160gb spinpoint (JVC motor), purchased about 6 months later).

The raid is software, done by my P5B Deluxe motherboard (ICH8R, 6 sata ports, but only 4 support raid).

The raid is my Windows XP drive (bootable), but I've other hard drives with WinXP and Ubuntu, so I'll try any tool recommended.

Any help very much appreciated.

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Post by Trekmeister » Mon Dec 17, 2007 2:57 pm

Well you could try to dd the entire disk content from the failing disk to the replacement disk in linux... Not sure it would work, and even worse I don't know what the raid software might do if it decides the array it is broken after you switch the disks. It should not overwrite anything, but you never know...

Something like
dd if=/dev/sda of=/dev/sdb bs=1000000
with 'if' beeing the bad drive and 'of' the good drive.

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Post by jojo4u » Mon Dec 17, 2007 5:55 pm

Yeah good 'ol dd. wrote: dd
The name dd stands for "copy and convert". Don't see it? Well, "cc" was already taken for the C compiler, so the author chose the next letter in the alphabet. The syntax has sort of an evil, JCL-like quality to it. According to The Jargon File, the interface was a prank.

dd /dee-dee/ /vt./

[Unix: from IBM JCL] Equivalent to cat or BLT. Originally the name of a Unix copy command with special options suitable for block-oriented devices; it was often used in heavy-handed system maintenance, as in "Let's dd the root partition onto a tape, then use the boot PROM to load it back on to a new disk". The Unix dd(1) was designed with a weird, distinctly non-Unixy keyword option syntax reminiscent of IBM System/360 JCL (which had an elaborate DD `Dataset Definition' specification for I/O devices); though the command filled a need, the interface design was clearly a prank. The jargon usage is now very rare outside Unix sites and now nearly obsolete even there, as dd(1) has been deprecated for a long time (though it has no exact replacement). The term has been displaced by BLT or simple English `copy'.
So it's deprecated has a very odd interface but no replacement ;)

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Post by NeilBlanchard » Mon Dec 17, 2007 6:47 pm


GetDataBack may be able to recover and reconstruct the RAID data:

You can try it, and if it works, then pay for the license and copy the data to another drive. It has worked well for me on regular NTFS drives, and RAID 1 drives, too. It is supposed to work with RAID 0 and RAID 5 drives.

Edit: there is a separate program called RAID Reconstructor:
Sincerely, Neil

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Post by theycallmebruce » Mon Dec 17, 2007 7:39 pm

A tool which does a sector by sector copy may do the trick. I don't know much about RAID, but I'm guessing if the drives are the same and the data is identical, it may work.

I use hiren's boot CD, which contains a copy of Norton Ghost.

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