[kwlug-disc] Recovering a software raided machine.

[unsolicited]

Not sure there's any need to dd the drive. Others will know the specific 
mdadm steps - I don't.

Assuming the drive is indeed a mirror, not a stripe.

You haven't said if there was anything wrong with the disk(s) causing 
you to land you where you got. If not, and a mirror, just leave one 
drive disconnected. The mirror will be degraded, but once mounted under 
knoppix, then chroot'ed, fix whatever you need to fix, probably install 
grub or maybe only update-grub. You should be able to then just boot and 
get on with your day. Once you feel you're solid, plug the other drive 
back in and tell it to sync. (See others for any mdadm commands.)

Sorry, I wasn't clear before.  Do what you gotta do to follow the below, 
meant to follow the prior post of:

 >>> This usually means that BIOS can't find boot loader. So, boot in
 >>> rescue mode or from different boot partition, and reinstall boot
 >>> loader (grub, lilo).

If it all goes to heck, you'll always have the other drive to fall back 
upon. Assuming it was mirrored not striped, and it was up to sync before 
your issues started.


On 14-03-11 04:26 PM, Joe Wennechuk wrote:
> Thank you for this. I got knoppix to boot up, and I am dd'ing the
> drive right now before I try any repair steps. I dd'd only the
> partition /dev/sdb1,  it is the only partition on the drive. I was
> wondering does anyone know should I have dd'd  /dev/sdb instead of
> /dev/sdb1 ?? What is the difference?
>
> ----------------------------------------
>> Date: Tue, 11 Mar 2014 15:17:45 -0400 From: unsolicited at swiz.ca To:
>> kwlug-disc at kwlug.org Subject: Re: [kwlug-disc] Recovering a
>> software raided machine.
>>
>> Boot favourite distro, chroot into your disks (once you get them
>> mounted with the live cd). Do what you gotta do to follow the
>> below.
>>
>> Been here, done this! (Remembered to put it in tiddlywiki, even.)
>>
>> mkdir /mnt/chroot mount /dev/sda1 /mnt/chroot for i in dev sys
>> proc; do mount -o bind /$i /mnt/chroot/$i; done chroot /mnt/chroot
>>
>> update-grub <eeyyy>
>>
>>
>> eeyyy - etc., etc., yada, yada, yada
>>
>>
>> On 14-03-11 01:22 PM, William Park wrote:
>>> On Tue, Mar 11, 2014 at 10:36:57AM -0400, Joe Wennechuk wrote:
>>>> I have a machine that will not boot. I'm getting a message to
>>>> insert boot media after post, and that's it.
>>>
>>> This usually means that BIOS can't find boot loader. So, boot in
>>> rescue mode or from different boot partition, and reinstall boot
>>> loader (grub, lilo).
>>>
>>>> It has two drives in it, and I believe they were set up as a
>>>> mirror using mdadm. Can I just take one or both of the drives
>>>> out, and plug it in via USB converter? Is there anything I will
>>>> have to do besides that?