Re: RAID1 all bootable

On Wed, Mar 6, 2013 at 8:38 AM, Bob Proulx <[email protected]> wrote:
> Francesco Pietra wrote:
>> Bob Proulx wrote:
>> > Francesco Pietra wrote:
>> >> Thanks so much for this manual. Unfortunately, I have no more the
>> >> initial situation (one HD replaced) because I was hurried by an editor
>> >> to provide computational data from my CUDA server. I did not want to
>> >> run the server before all my data were backed up. Therefore I did a
>> >> fresh amd64 wheezy install on both disks, the old one and the newly
>> >> replaced. The installation ended with:
>> >
>> > Sad to see that you have given up already and destroyed your data.
>>
>> I had all my data on another raid1 machine. Following the new install,
>> all data were scp transferred. All my machine are on a router, with
>> passwordless scp. Which is also used to contact external server for
>> computational work.
>
> Oh!  Okay.  I thought you had installed over it.  I see now that you
> installed upon a different system and copied over to it.  Very good.
>
>> Following a seemingly correct installation, with grub installed
>> 'grub-install /dev/sda' and 'update grub'
>>
>> command
>>
>>  grub-install /dev/sdb
>>
>> led to a system that did no more boot. I can't see what was wrong with
>> the installation. I have now the same situation (install from the
>> wheezy installer). If you suggest what to check, I'll do that.
>
> I can't think of any reason for that to fail.  It works for me.  (I do
> always set up a separate /boot but a /boot that is also on RAID1.  But
> it eliminates the LVM interaction.  Which previously was not supported
> but now as I understand it is fully supported.)  I am sorry but I
> cannot think of anything to suggest.
>
> I always found grub 1 easier to debug than grub 2.  With grub 1 it was
> possible to do something like this:
>
> Verify that the grub files are on both disks:
>
>   grub>find /grub/stage1
>   (hd0,0)
>   (hd1,0)
>
> Install grub onto the second disk:
>
>   grub> device (hd0) /dev/sdb
>   grub> root (hd0,0)
>   grub> setup (hd0)
>   grub> quit
>
> But now with grub 2 there is only the install script:
>
>   grub-install /dev/sdb
>
> I can only suggest that if you have the resources set up a "victim"
> machine and do test installations and then try different combinations
> in order to learn enough about the problem in order to debug it.

I had the same idea, though, at the moment, there is no such "victim"
machine, and duties are pressing: classes, research, shortage of money
(I am based in Italy, you know the situation from the media).

I'll explore with Knoppix. Through Knoppix, in the past, I was able to
look into my md0 (boot) and md1 (LVM). I could mount sda and look into
it, detecting grub (don't remember which version). However, I did not
try to install grub from Knoppix, although it should be feasible.

Have a nice day

francesco pietra


>
>> Thanks a lot for your generous help. I (we) learned a lot from you.
>
> Happy to help.  I only wish it could have been more useful.
>
> Bob
>
>
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