Arch Linux

surfatwork

Member

Registered: 2012-01-05

Posts: 137

Add partition to btrfs pool

Apologies if this is a noob question - I am new to btrfs. I wasnt able to get this answered satisfactorily from the wiki and by googling.

I have a btrfs pool on /dev/sda13. Three subvolumes - root, home, var - which house the arch filesystem, mounted on /, /home and /var respectively.
a partition has come free on the disk (/dev/sda5), which I would like to add to this pool.

Would the following be the correct way to do it?

# mkfs.btrfs /dev/sda5
# btrfs device add /dev/sda5 / 
# btrfs filesystem balance /

thanks,

nstgc

Member

Registered: 2014-03-17

Posts: 393

Re: Add partition to btrfs pool

You don't need to rebalance, however I would advise it. Do know that the volume resulting from those commands would be a "single". You would need to use "# btrfs bal start -dconvert=raidX -mconvert=raidY" for X,Y in {0,1,5,6,10} for something else. Also I believe there is currently a bug in btrfs-progs or the kernel making something along these things impossible. I can't remember, but i think it only effects RAID1.