[ILUG] Booting a broken raid array

[John Allen]

Kevin Philp wrote:
> David Golden wrote:
>> On Thursday 15 January 2009, Ciaran Johnston wrote:
>>
>>  
>>> Having /boot configured this way means that, no matter which disk
>>> fails the other will still boot in degraded mode.
>>>
>>>     
>>
>> Do watch out for bootloader setup - remember you want a 1st stage
>> bootblock on each physical disk. Your distro and/or bootloader* may 
>> not automagically get it right, even today.  If in doubt, check!
>>   
> Just to get this 100% correct. I should install grub on the MBR of 
> each disk rather than onto a partition:
>
> Such as:
>
> # grub-install /dev/hda
> # grub-install /dev/hdb
> # grub-install /dev/hdc
>
> Then I could boot of any disk should one fail.
>
Yes, thats exactly what I do. Oh, and try it out before you commit to 
live, and ensure you know the mdadm magic to hot add the partitions back 
to the array.

For installation I typically partition disk 1 (using cfdisk), and do
sfdisk -d /dev/sda | sfdisk /dev/sdX

for each subsequent disk (replacing X with b, c, d etc...)

quick and easy identical partitions on all disks.
>
>> * These days I favour extlinux, it's no-nonsense compared
>> to grub, especially if you're only booting linux anyway,
>> but less primitive than lilo.
>> http://syslinux.zytor.com/wiki/index.php/EXTLINUX
>>   
>