mdadm
RAID5
You will need 4 disks and the mdadm
package.
The total size will be equal to the disks x 3, because one will be used for redundancy.
sudo mdadm --create --verbose /dev/*md127* --level=5 --raid-devices=*4* */dev/sdb /dev/sdc /dev/sdd /dev/sde*
Note the variable parts:
- The name of the device could be
/dev/md12
or whatever - The number of devices could be larger, but must be at least 4 for raid 5
- We end by listing all devices in the new
md
device.
Now look at how the raid status:
cat /proc/mdstat
This will increase until the entire thing is fine.
Check the health of your mdadm
array:
sudo mdadm --detail /dev/md127
You should see State : clean
. If you see it is degraded
, then a disk has broken.
Replacing a Disk
sudo mdadm --add /dev/md127 /dev/sdb1