[ILUG] Booting a broken raid array
john.allen at dublinux.net
Fri Jan 16 11:45:37 GMT 2009
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.
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