[CentOS] raid 1

Sat Apr 28 05:24:03 UTC 2007
CentOS List <centoslist at gmail.com>

> 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
>>
>> If swapped and booted, and got a kernel panic error.
>
>>> 'linux rescue' at the boot prompt, let it detect and mount your system 
>>> (which will be the 'broken' raid devices with their single members),
>>
>> If i use linux rescue, The 3 mds I created are gone. /cat /proc/mdstat 
>> says Personalitlies: [raid0] [raid1] [raid5] [raid6], no longer 
>> Personalities : [raid1]
>
> Perhaps your raid wasn't really working the way you thought before. From 
> the rescue boot, does fdisk show the 3 partitions on the old disk with 
> type 'fd'?  Can you mount the old /boot and / partitions somewhere by 
> hand?  You should be able to do this with the /dev/sda1 and /dev/sda3 
> device names if the md devices aren't detected at boot.

cat /proc/partitions still shows me the 3 partitions.  I actually copied 
/boot to the "replaced disk" and it is able to boot up, but without any 
filesystem, so i guess the boot is still intact. So do i need to mount /boot 
and /?