Replacing a failed drive in an md raid1/raid10
- Check
# mdadm --detail /dev/md0- If in an array a partition of the failed drive is not marked as faulty, run
# mdadm --manage /dev/md1 --fail /dev/sda2 - If the kernel doesn't already removed the faild drive from the arrays, remove it by hand:
# mdadm /dev/md0 --remove /dev/sda1
- If in an array a partition of the failed drive is not marked as faulty, run
- Insert a new physical disk
- Copy the partition table to the new drive from its mirror:
- For gpt partition table:
# sgdisk -R /dev/sda /dev/sdb(fromsdbtosda)# sgdisk -G /dev/sda(to make the new disk's GUID different the mirror's one)
- For mbr partition table:
# sfdisk --dump /dev/sdb | sfdisk /dev/sda
- For gpt partition table:
- Add the new drive into the arrays:
# mdadm /dev/md0 --add /dev/sda1- In case of error
mdadm: Cannot open /dev/sda1: Device or resource busy
check if the md subsystem creates /dev/md127 from /dev/sda1. In this case run mdadm --stop /dev/md127 and then re-run mdadm /dev/md0 --add /dev/sda1
- Update
/etc/smartd.conf - Observe the mirroring process with
$ watch cat /proc/mdstat