> CentOS List wrote: >>> 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. > > Does fdisk say that they are type 'fd'(raid autodetect)? > >> 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 /? > > If you can get the original partitions to be detected as their md devices > you should fdisk matching partitions on the replacement disk, then > 'mdadm --add ...' to add them and they will automatically sync up. mdadm --create --verbose /dev/md0 --level=1 --raid-devices=2 /dev/sda1 /dev/sdb1 mdadm --create --verbose /dev/md1 --level=1 --raid-devices=2 /dev/sda2 /dev/sdb2 mdadm --create --verbose /dev/md2 --level=1 --raid-devices=2 /dev/sda3 /dev/sdb3 After that i reboot and got the kernel panic again. md: considering sdb1 md: adding sdb1 md: created md0 md: bind<sda1> md: running: <sdb1><sda1> raid1: raid set md0 active with 2 out of 2 mirrors md: ... autorun DONE md: autodetcting RAID arrays md:mautorun ... Creating root device Mounting root filesystem switching to new root switchroot: mount failed: 22 umount /unitrd/dev failed: 2 Kernel panic