corrupt raid 5, repair/recreate raid?

  • Thread starter OTWarrior via HWKB.com
  • Start date
O

OTWarrior via HWKB.com

I have 3 hard disks in a raid 5 and yesterday, one of the disk "failed". So I
selected the option to repair the raid on the drive (which has worked before),
and after about 2 hours, it blue screened my computer.

now it will not boot up, as the WHOLE raid has failed.

Is there a way of recreating the raid without losing my data?

the Bios/Dos utility for the Raid allows me to:
1) create a raid (not enough space)
2) delete a raid (dont want to delete it)
3) reformat drives to non -raid (this sounds promising if it keeps my data)

Please could someone advise me on what to do? as I have a 250gb hard disk on
that computer, and I would hate to have to install all of my games again
(especially WOW with all the patches ;)

if I were to convert it to a non-raid, would that still enable me to view my
data?

if I replace the hard drive that failed before, would that help? and how
would I "input" it into the raid?
 
A

Arno Wagner

Previously OTWarrior via HWKB.com said:
I have 3 hard disks in a raid 5 and yesterday, one of the disk
"failed". So I selected the option to repair the raid on the drive
(which has worked before), and after about 2 hours, it blue screened
my computer.

Have you tracked down the reason of the problem?
now it will not boot up, as the WHOLE raid has failed.
Is there a way of recreating the raid without losing my data?
the Bios/Dos utility for the Raid allows me to:
1) create a raid (not enough space)
2) delete a raid (dont want to delete it)
3) reformat drives to non -raid (this sounds promising if it keeps my data)

As far as I can tell, all these options will erase your data.
Please could someone advise me on what to do? as I have a 250gb hard
disk on that computer, and I would hate to have to install all of my
games again (especially WOW with all the patches ;)
if I were to convert it to a non-raid, would that still enable me to
view my data?

No. The RAID software and controller do not understand filesystems.
They cannot convert your data to non-raided.
if I replace the hard drive that failed before, would that help? and how
would I "input" it into the raid?

You should have done that in the first place. On how to
do it, refer to the documentation of your RAID controller.

Arno
 
N

Nik Simpson

OTWarrior said:
I have 3 hard disks in a raid 5 and yesterday, one of the disk "failed". So I
selected the option to repair the raid on the drive (which has worked before),
and after about 2 hours, it blue screened my computer.

Did you investigate the failed drive at all or did you just put it back
online and hope?
now it will not boot up, as the WHOLE raid has failed.

You've probably corrupted the RAID set beyond repair.
Is there a way of recreating the raid without losing my data?

Probably not, if a RAID-5 has been corrupted so that data and parity no
longer match, there's not much you can do except restore from backup.
You do have a backup?
the Bios/Dos utility for the Raid allows me to:
1) create a raid (not enough space)
2) delete a raid (dont want to delete it)
3) reformat drives to non -raid (this sounds promising if it keeps my data)

Please could someone advise me on what to do? as I have a 250gb hard disk on
that computer, and I would hate to have to install all of my games again
(especially WOW with all the patches ;)

if I were to convert it to a non-raid, would that still enable me to view my
data?

Nope, the data and parity are striped across all the drives in the set,
so no single drive has anything approaching usable data.
if I replace the hard drive that failed before, would that help? and how
would I "input" it into the raid?

It might help, certainly can't hurt.
 
M

Michael Hawes

OTWarrior via HWKB.com said:
I have 3 hard disks in a raid 5 and yesterday, one of the disk "failed". So
I
selected the option to repair the raid on the drive (which has worked
before),
and after about 2 hours, it blue screened my computer.

now it will not boot up, as the WHOLE raid has failed.

Is there a way of recreating the raid without losing my data?

the Bios/Dos utility for the Raid allows me to:
1) create a raid (not enough space)
2) delete a raid (dont want to delete it)
3) reformat drives to non -raid (this sounds promising if it keeps my
data)

Please could someone advise me on what to do? as I have a 250gb hard disk
on
that computer, and I would hate to have to install all of my games again
(especially WOW with all the patches ;)

if I were to convert it to a non-raid, would that still enable me to view
my
data?

if I replace the hard drive that failed before, would that help? and how
would I "input" it into the raid?
When you startup is the raid array still shown during POST? If there is
no room create a RAID, the original array should be available to view.If you
replace the original faulty drive, you then enable it for RAID and set it to
rebuild. If the 2 disks have got corrupted, you are out of luck. Start again
and restore from your backup. You should have tested the faulty drive with
manufacturers diagnostic before attempting a repair. If this drive has
failed before, you should have taken the hint.

Mike.
 
O

OTWarrior via HWKB.com

1) how would I investigate a failed drive? the only option available was to
mark as normal and restore the raid (which was the advice I was given before)

2)
Probably not, if a RAID-5 has been corrupted so that data and parity no
longer match, there's not much you can do except restore from backup.
You do have a backup?

no I do not have a backup as this is my gaming PC and doesn't hold critical
files, over than save games/mods. I was also told that Raid 5 would be more
secure and reliable than a normal hardisk setup, and Raid 5 should work with
1 drive that has failed, why would restoring the Raid damage the whole thing?

And surely the Raid is more like a list of where parts of files are held, so
you could recreate it (almost). There must be some kind of utility out there
to repair raids? if they can get imformation of a burnt hard disk, then you
should be able to get the infomration of a corrupted raid.

3) >> if I replace the hard drive that failed before, would that help? and
how
You should have done that in the first place. On how to
do it, refer to the documentation of your RAID controller.

Raid controller? would that be the motherboard? or the software that is
installed in windows for the raid? or the bios/dos raid screen in bootup?


4) >Nope, the data and parity are striped across all the drives in the set,
so no single drive has anything approaching usable data.

Raid 5 can function with 2 working drives, so the full data must be on 2 of
them, with the 3rd as a backup.

Thanks for the help so far, I just want to clarify your suggestions/answers.
 
M

Michael Hawes

OTWarrior via HWKB.com said:
1) how would I investigate a failed drive? the only option available was
to
mark as normal and restore the raid (which was the advice I was given
before)

2)


no I do not have a backup as this is my gaming PC and doesn't hold
critical
files, over than save games/mods. I was also told that Raid 5 would be
more
secure and reliable than a normal hardisk setup, and Raid 5 should work
with
1 drive that has failed, why would restoring the Raid damage the whole
thing?

And surely the Raid is more like a list of where parts of files are held,
so
you could recreate it (almost). There must be some kind of utility out
there
to repair raids? if they can get imformation of a burnt hard disk, then
you
should be able to get the infomration of a corrupted raid.

3) >> if I replace the hard drive that failed before, would that help? and
how


Raid controller? would that be the motherboard? or the software that is
installed in windows for the raid? or the bios/dos raid screen in bootup?

How did you setup the array? If it is an option during the startup, it is
raid controller on motherboard (or add-in card?) If the drives are
configured as Dynamic Disks, using software RAID, that is slower than
hardware RAID controller and is controlled through Windows.
 
N

Nik Simpson

OTWarrior said:
And surely the Raid is more like a list of where parts of files are held, so
you could recreate it (almost). There must be some kind of utility out there
to repair raids? if they can get imformation of a burnt hard disk, then you
should be able to get the infomration of a corrupted raid.

The problem is that at this point, you don't what data is good and what
data is corrupt, and even if you did, 1/3rd of all the blocks in the
RAID set (i.e. one drive) is completely FUBAR. So there is no way to
reconstruct the data with any degree of confidence.
3) >> if I replace the hard drive that failed before, would that help? and
how


Raid controller? would that be the motherboard? or the software that is
installed in windows for the raid? or the bios/dos raid screen in bootup?


4) >Nope, the data and parity are striped across all the drives in the set,

Raid 5 can function with 2 working drives, so the full data must be on 2 of
them, with the 3rd as a backup.

That's not how it works, XOR parity is distributed acorss the sdrives
along with data. If one drive fails, then data from the remaining drives
along with the XOR inforamtion is used to recreate the missing drive.
However, if the conttroller has got to a point where the parity or data
is corrupted then there is no way to rebuilod the missing data.
Thanks for the help so far, I just want to clarify your suggestions/answers.
If it's simply failed because the third drive is bad, then replacing the
third drive with a new drive and attempting the rebuild again *might*
work, but no guarantees.
 
O

OTWarrior via HWKB.com

I deleted the Raid, and now running in non raid format. However, I have only
been able to format one drive.

It has been a while since I have had to rebuild a pc, so how would I format
the other drives? I cannot seem to get to the command system, the only boot
options I have are "boot from Hard disk" or "boot from cd" (this is when I
press F8 when the ram is being counted)

What do I need to do to clear the other disks?
 
A

Arno Wagner

Previously OTWarrior via HWKB.com said:
Sorry Arno Wagner, you post didn't show, could you post again please.

Yes, an old problem with my newsreader.

What you can do is to blank the other drives with one
of the various methods proposed in this group. Set them
to non-raided or connect them to a non-raided interface
before you do this.

Personally I use a Knoppix CD-Linux for this. A lot of other
options exist.

Arno
 

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