Compression: per filesystem, or per subvolume?

Compression: per filesystem, or per subvolume?

[Fajar A. Nugraha]

Currently using Ubuntu Natty, kernel 2.6.38-9-generic, I have these
mount points using btrs subvolumes

$ mount -t btrfs
/dev/sda2 on / type btrfs (rw,noatime,subvolid=256,compress-force=zlib)
/dev/sda2 on /home type btrfs (rw,noatime,subvolid=258,compress=lzo)

Yet dmesg seems to show only zlib compression enabled
$ dmesg | grep btrfs
[   11.097908] btrfs: force zlib compression

Is this by design, or a bug?

-- 
Fajar

Re: Compression: per filesystem, or per subvolume?

[kehon]

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At the moment btrfs doesn't support separate compression for volumes on
the same filesystem.

On 05/08/11 at 08:35pm, Fajar A. Nugraha wrote:
> Currently using Ubuntu Natty, kernel 2.6.38-9-generic, I have these
> mount points using btrs subvolumes
> 
> $ mount -t btrfs
> /dev/sda2 on / type btrfs (rw,noatime,subvolid=256,compress-force=zlib)
> /dev/sda2 on /home type btrfs (rw,noatime,subvolid=258,compress=lzo)
> 
> Yet dmesg seems to show only zlib compression enabled
> $ dmesg | grep btrfs
> [   11.097908] btrfs: force zlib compression
> 
> Is this by design, or a bug?
> 
> -- 
> Fajar
> --
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Re: Compression: per filesystem, or per subvolume?

[Fajar A. Nugraha]

On Sun, May 8, 2011 at 8:38 PM, cwillu <cwillu@gmail.com> wrote:
> It's by not-implemented-yet.=A0 Mount options are still currently glo=
bal to
> the filesystem.

Thanks for the info. I was testing combination of grub2, btrfs "/"
without separate /boot, and lzo. Using lzo feels much faster compared
to zlib, so right now I just use separate /boot/grub in ext4 to make
it work correctly.

--=20
=46ajar

>
> On May 8, 2011 7:35 AM, "Fajar A. Nugraha" <list@fajar.net> wrote:
>> Currently using Ubuntu Natty, kernel 2.6.38-9-generic, I have these
>> mount points using btrs subvolumes
>>
>> $ mount -t btrfs
>> /dev/sda2 on / type btrfs (rw,noatime,subvolid=3D256,compress-force=3D=
zlib)
>> /dev/sda2 on /home type btrfs (rw,noatime,subvolid=3D258,compress=3D=
lzo)
>>
>> Yet dmesg seems to show only zlib compression enabled
>> $ dmesg | grep btrfs
>> [ 11.097908] btrfs: force zlib compression
>>
>> Is this by design, or a bug?
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