설치하다.

apt install -y mdadm

새 RAID1

mdadm --create /dev/md0 --level=1 --raid-devices=2 /dev/sdb /dev/sdc
mkfs.ext4 /dev/md0

mdadm --create /dev/md1 --level=1 --raid-devices=2 /dev/sda /dev/sdd
mkfs.ext4 /dev/md1

OS 시작 시 마운트

mdadm --detail --scan
mdadm --detail --scan > /etc/mdadm.conf

복구 확인

cat /proc/mdstat

DISK 장애 대응

mdadm --detail /dev/md0

- State : clean, degraded
  ...
    Number   Major   Minor   RaidDevice State
       0       8        0        0      active sync   /dev/sdb
-      2       0        0        2      removed

mdadm --manage /dev/md0 --remove /dev/sdc
mdadm --manage /dev/md0 --fail /dev/sdc

mdadm --manage /dev/md0 --add /dev/sdc

+ State : active, degraded, recovering
  ...
    Number   Major   Minor   RaidDevice State
       0       8        0        0      active sync   /dev/sdb
+      2       8       48        1      spare rebuilding   /dev/sdc