RAID

Raid allows for data to be sparsed over multiple disks and give security to your data as one (or more) disks can fail and data integrity will still remain.

Initialize disks

mdadm --zero-superblock /dev/sd[b-e]

or

wipefs -a /dev/sd[b-e]

Create raid

You can set level to get more performance or more redundancy

This command will create a raid level 10.

mdadm --create /dev/md0 --level=10 --raid-devices=4 /dev/sd[b-e] 

Check raid types and benefits here: http://www.raid-calculator.com/

Save your newly created raid configuration for next reboots:

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

Utils

  • cat /proc/mdstat: shows raid status and progress

Considerations

mdadm software raid will trigger a complete check every sunday at 1am. Be aware of that as it will lower diks io speed a lot.