[CentOS] raid 1

[Les Mikesell]

CentOS List wrote:

>>>
>>> I am running raid 1 on a centos 4.4. One of the harddisk (sda1) 
>>> failed. How can i carry on running the server using only sda2?
>>
>> Generate a grub floppy and use that to load the grub menu from the sdb 
>> (probably now sda) disk.
>>
>> If you are really talking about sda1 and sda2, those are partitions on 
>> the same disk.
> 
> Is there a detail step by step howto? The raid 1 has no LVM. just md0, 
> md1 and md2. md0 is /boot, md1 is swap and md2 is the storage. I had 
> replace sba with a new disk. I tried to boot up and it says kernel 
> panic. How am i going to reconstruct the raid and sync sdb to sda?

It might be easier to swap the old sdb into the sda position so you'll 
boot from it, but you should also be able to boot the install cd with
'linux rescue' at the boot prompt, let it detect and mount your system 
(which will be the 'broken' raid devices with their single members), 
then do the chroot command it suggests.  From there you can fdisk 
matching partitions on the new sda disk (if you didn't swap) and use 
mdadm to add them to the RAIDs.  Or you can just install grub on sda so 
you can reboot normally, then sync the mirrors with mdadm after you are 
running.

-- 
  Les Mikesell
    lesmikesell at gmail.com