Re: Help! Repairing a RAID 1 dynamic disk

I would NOT do the described procedure. ('cept maybe the bit about ensuring
you have a good backup)

I don't have an out of sync array at the moment to check the terminology but
in Disk Management the out of sync partition should be indicating it is so.
If you rt-clk on one of the partition partners you should have an option to
'rebuild' or 'resync' or 're-establish' the mirror.

Do not restart the system while the array is rebuilding or it will stop
doing so, let it complete the rebuild then restart and inspect the array.

If it fails to rebuild it indicates an error during the rebuild process,
often due to bad sectors on either the 'source' or 'target' drive but can
also be due to other factors, such as HDD IO. If the rebuild fails you might
try stopping unnecessary services, Exchange, AV, SQL (things which are
necessary for normal operation but not necessary to the OS).

If it still fails. CHECK THREE TIMES before going into the SCSI bios and
seeing if it supports formatting of the HDD. MAKE SURE you format the out of
sync drive. This will delete all partition information from the drive,
including the 'dynamic' description. restart, convert the drive to dynamic
format, re-establish the mirror.

NOTE: these days, not all controllers/drives support SCSI low level format.

If the SCSI bios does not support low level format. Shutdown. Disconnect the
failed drive. Reboot with just the good drive connected. Ensure all is OK
and shutdown again. Disconnect the good drive, connect the bad. Boot off any
Windows installation CD (SBS CD1 will do, as would a 2000/XP pro CD). As you
go through the early stages of the installation you will be asked which
partition to install to. At this time you can delete the existing partitions
and exit the installation. (I'm normally paranoid at this point, reboot off
the CD again and continue to the same point, ensure all the partitions have
been deleted. A _REALLY_ paranoid individual would continue through until
the partitions are formatted, then return and delete it again.). Reconnect
your good drive, boot, re-establish mirrors.

NOTE: Depending on the controller you may do well to set the good drive as
SCSI ID0, if it is not already.

"Nick Oliver" <nicko@xxxxxxxxxxxxxxxxx> wrote in message
news:eXKd%23jlWGHA.4768@xxxxxxxxxxxxxxxxxxxxxxx
Alan,

1. Get a good backup
2. Break the mirror
3. Reboot the machine to the primary drive (0). Take out the other if you
need to to verify.
4. When you know that is done, reboot the server (to the same drive) with
the other drive back in place.
5. In Windows, go ahead and reconfigure the mirror.

You can shortcut all this just by breaking and rebuilding the mirror, your
choice.

Good luck,

Nick



"Alan P." <alanp@xxxxxxxxx> wrote in message
news:TluZf.6346$gO.533@xxxxxxxxxxx
I've got a production system here that I've inherited and need a
little advice - and my boss is riding my ass for an update asap.

Its a Dell Windows 2000 server with two SCSI hard drives running
off the m/b's on-board SCSI controller.
The controller is not a raid controller, just a U320 scsi.

The two drives are configured with dynamic disk and software RAID
1 mirroring.

There are two partitions on the hard drive system - C:OS and
D:data.

When I browse the hard drives using the MS disk management
utility, I see not one hard drive, but two.
And each hard drive shows the C and D partitions.

So here's the problem:

The disk 0's C:OS partition is no longer synced to the disk 1's
C:OS partition. The D:data mirrored partition shows as the RAID
mirroring as ok.

I have rebooted the box and used the on-board SCSI utility to
verify the disk that claims to have failed with a read/write test
that has found no defects. I'm thinking (guessing) there is no
real problem with this partition and that it just needs to be
re-synced.

So how do I do this, safely, without hosing the box?

----

Traditionally, I've use hardware SCSI RAID controllers to provide
the RAID safety. I've never worked with MS's dynamic disks and
their software RAID, so I'm really worried about trashing the OS.

My assumption is that I would try a re-sync on the C:OS partition
and see if the box can repair itself for now. If the re-sync come
back with the same error and we are again operating the OS on just
one hard drive, then I'd need to come up with a better solution,
soon.

In situations like this in the past, I'd hookup a spare drive and
snap a Ghost image of the server for safety.
I have access to and am pretty familiar with Ghost Corporate
edition 7.5, but I think it's not compatible with dynamic disks ??

---

Could anyone having experience with this situation / MS dynamic
disk RAID please offer some tips here?

I just need to know the sequence I should use to try to get the
software RAID to repair itself, for now.

Please repsond to this group - any tips or suggestions would be
really welcome!

Thanks Alan.






.

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