Moving a server over to a RAID

[Tom H]

On Thu, Aug 19, 2010 at 12:09 PM, Rashkae <ubuntu at tigershaunt.com> wrote:
> Mike A. Leonetti wrote:
>>  I have a server now that has one drive and is not set up on a RAID
>> using Ubuntu 8.04.
>>
>> What I was going to do was boot with a Linux recovery disc, create a
>> RAID1 manually with mdadm on two new drives, and then copy all of the
>> data onto that then redo the boot partition.
>>
>> My question is, when I reboot, will Ubuntu automatically detect the RAID
>> for me or are there modules I have to install ahead of time to make sure
>> the RAID gets detected? Also, would anybody else handle the situation
>> differently :D.
>
> There is going to be one hurdle you'll need to get over.. I forget the
> exact command I used to recover, but I'll give you the overview.
>
> When raid array's are created, they are given a "hostname", which, by
> default, will by the system hostname.  By default, mdadm will not
> auto-assemble raid arrays from a different hostname (to prevent
> misunderstandings when hard drives are moved between different systems.)

You can update the homoehost in the superblock when you assemble an array.