I had mirror raid disk faulty today so I need to swap one disk in array
It was /dev/sda hard drive
So to to this I need to remove it from raid and then add another disk into it.
Removing broken one
cat /proc/mdstat
mdadm --manage /dev/md0 --fail /dev/sda1
mdadm --manage /dev/md1 --fail /dev/sda2
mdadm --manage /dev/md2 --fail /dev/sda3
cat /proc/mdstat
mdadm --manage /dev/md0 --remove /dev/sda1
mdadm --manage /dev/md1 --remove /dev/sda2
mdadm --manage /dev/md2 --remove /dev/sda3
cat /proc/mdstat
shutdown -h now
Adding The New Hard Disk
if you have common partition table you just need to do:
sfdisk -d /dev/sdb | sfdisk --Linux /dev/sda
but in my case GUID partition table used so I need to use:
sgdisk -R=/dev/sda /dev/sdb
sgdisk -G /dev/sda
mdadm --manage /dev/md0 --add /dev/sda1
mdadm --manage /dev/md1 --add /dev/sda2
mdadm --manage /dev/md2 --add /dev/sda3
cat /proc/mdstat
or if you going to watch how it is rebuilder
watch cat /proc/mdstat