[sheepdog-users] sheep and no compression object files putted on btrfs & zfs

[Hitoshi Mitake]

At Wed, 27 May 2015 14:00:06 +0200,
Marcin Mirosław wrote:
> 
> Hi!
> I'd like to reanimate my old question. I put sheep on btrfs mounted with
> compress-force=lzo. Files created manually (using dd from /dev/zero) are
> compressed very well on this filesystem, as expected. When I create vdi,
> write zeroes to vdi then disk usage on btrfs grows at the same level as
> summary size of files created by sheep.
> It means that btrfs, even with compress-force, doesn't compress files.
> What is the reason of this behavior? How can I change it and allow btrfs
> to compress files?
> I did test on zfs, it works corrrectly, zfs compressed files without
> problem.

I don't know the detail of the btrfs compression feature. But sheep
creates object files with fallocate() for better disk layout. It would
be preventing compression, I guess.

Thanks,
Hitoshi

> 
> Marcin
> 
> -- 
> sheepdog-users mailing lists
> sheepdog-users at lists.wpkg.org
> https://lists.wpkg.org/mailman/listinfo/sheepdog-users