Re: [gentoo-user] boot problems

[Tom H]

On Sun, May 4, 2014 at 2:48 PM, J. Roeleveld <joost@××××××××.org> wrote:
> On Sunday, May 04, 2014 01:15:51 PM Neil Bothwick wrote:
>> On Sat, 03 May 2014 20:40:47 +0200, J. Roeleveld wrote:
>>>>
>>>> * SystemRescueCD and the Gentoo minimal installation CD both start
>>>> any raid arrays they find and apply their own names to them. It is
>>>> then impossible, or so I thought, to resume an interrupted
>>>> installation process. Of course, all I had to do was "mdadm
>>>> --stop /dev/md127" etc.
>>>
>>> Yes, I noticed that annoyance myself. I would much prefer it to default
>>> to more logical names.
>>
>> ISTR that's because of the hostname stored in the RAID, so when you plug
>> the array into another computer, it doesn't clobber any existing array
>> names. I had this happen when transplanting an array to a new system.
>> There is a sequence of commands to reset the names but it was a while ago
>> and all I remember is that the sequence started with "man lvm".
>
> Actually, the steps are:
> 1) invalidate the RAID
> 2) create a new, broken, RAID using the invalidatd disk
> 3) copy data to new RAID
> 4) delete md127
> 5) add other disk from md127 to md1
>
> Or something to that effect.
> A "rename" option or even a "I_KNOW_WHAT_I_AM_DOING_JUST_KEEP_THE_SAME_NAME"
> option, which would be enabled by default when booting with sysresccd, would
> be nice.

There's an mdadm option to change the hostname ("--homehost=<hostname>
--update=homehost") but in the case of 0.9 metadata it'll change the
uuid.

You can also set "HOMEHOST=none" in mdadm.conf before creating an
array, but I'm not sure how the md device will be numbered if you then
assemble it on a box with "HOMEHOST=system" set.