GNet Solutions » GNU/Linux Administration

I recently nuked my Raspberry Pi with an external btrfs RAID10 array, but I forgot to backup the fstab file. However setting up the array again is fairly simple. This is a guide on setting up an already made btrfs RAID10 array on Arch Linux.

Prepare the Environment¶

• Make sure the system is up to date:
  

  sudo pacman -Syu
  

• Install the btrfs-progs package:
  

  sudo pacman -S btrfs-progs
  

Configure the Array¶

• Scan all devices
  

  btrfs device scan
  

• Print information about all of the btrfs filesystems:
  

  btrfs filesystem show
  

  • This should output something similar to the following:
    

    Label: none  uuid: a881d8b5-6b33-4b1c-b02f-7062a853b89c
        Total devices 4 FS bytes used 161.50GiB
        devid    1 size 59.62GiB used 57.01GiB path /dev/sda
        devid    2 size 59.62GiB used 57.01GiB path /dev/sdb
        devid    3 size 119.25GiB used 116.00GiB path /dev/sdc
        devid    4 size 119.25GiB used 116.00GiB path /dev/sdd
    

• Make the mount path:
  

  sudo mkdir -p /media/usbraid
  

• Manually mount the btrfs RAID10 array:
  

  sudo mount /dev/disk/by-uuid/a881d8b5-6b33-4b1c-b02f-7062a853b89c /media/usbraid/
  

• Edit the fstab config:
  

  sudo nano /etc/fstab
  

  • And append the following to the end of the file:
    

    UUID=a881d8b5-6b33-4b1c-b02f-7062a853b89c     /media/usbraid    btrfs    device=/dev/sda,device=/dev/sdb,device=/dev/sdc,device=/dev/sdd    0 0
    

Resources¶

• https://btrfs.wiki.kernel.org/index.php/Using_Btrfs_with_Multiple_Devices