Arch Linux

eric

Member

From: under heaven

Registered: 2004-02-11

Posts: 117

[NOT YET POSSIBLE] how to compress only 1 subvolume with btrfs?

Hi, I'm trying to create 2 subvolumes on a partition on my harddisk and make only one use compression.

The problem is that whatever I do, either both or none use compression.

This is what I did:

cd /tmp
mkdir comp nocomp
mkfs.btrfs -L btrfs-root /dev/sdb1
mount /dev/sdb1 nocomp -t btrfs -o defaults
btrfs subvolume create nocomp/nocomp
btrfs subvolume create nocomp/comp
umount nocomp

Depending on the order of the next 2 commands, I get either both or none subvolumes use compression:

mount /dev/sdb1 comp -t btrfs -o defaults,subvol=comp,compress-force
mount /dev/sdb1 nocomp -t btrfs -o defaults,subvol=nocomp

To test if compression worked, I've copied a big text file (14MiB) to the subvolumes, did a 'sync' and then 'df'.

I've done research on the internet and also on Archlinux' wiki, but most information I've found was about installing (Arch)linux on a btrfs partition.

Last edited by eric (2011-09-27 22:36:44)

eric

Member

From: under heaven

Registered: 2004-02-11

Posts: 117

Re: [NOT YET POSSIBLE] how to compress only 1 subvolume with btrfs?

It looks like that this is not possible:
http://www.mail-archive.com/linux-btrfs … 05552.html
http://www.mail-archive.com/linux-btrfs … 09885.html

But I think they are working on it:
http://www.mail-archive.com/linux-btrfs … 12437.html