Booting machine after removing hard-disks from software raid array
From Notes_Wiki
Booting machine after removing hard-disk from software raid array
When we try to boot after removing one hard-disk in some cases the system may boot properly. In other cases it would give error that partition or device '/dev/md<n>' does not exists. In such case we have to boot using linux installation cd in rescue mode and follow these steps:
- chroot /mnt/sysimage
- more /proc/mdstat
- mdadm --auto-detect
- more /proc/mdstat
- mdadm --detail -sv
- mdadm --detail -sv > /etc/mdadm.conf
- sync
- exit
- exit
After this the system should boot. In case you have added new spare hard-disk then you must partition it appropriately. Use 'partprobe' to detect new partitions and then use 'mdadm' as explained above to add these new partitions in existing raid array.