[Systems] Which storage driver for Docker?

[Bernie Innocenti]

On 03/11/14 05:19, Sam P. wrote:
> Hey Bernie,
> 
> On Sun, Nov 2, 2014 at 3:47 PM, Bernie Innocenti <bernie at codewiz.org
> <mailto:bernie at codewiz.org>> wrote:
> 
>     I just read this:
> 
>     http://developerblog.redhat.com/2014/09/30/overview-storage-scalability-docker/
> 
>     Perhaps I've been too fast to ditch btrfs: docker really needs a
>     copy-on-write filesystem to store images efficiently... and btrfs is
>     slower and more complicated than other filesystems *exactly* because
>     it's designed to handle CoW well.
> 
> 
> Sounds cool
>  
> 
> 
>     So it's a perfect fit... if it works. I'm a bit worried that the Ubuntu
>     14.04 kernel might have serious btrfs bugs, but we have no way to know
>     until we hit one. Let's just make sure we have very good backups,
>     ok? :-)
> 
> 
> Well we have 2 btrfs partitions, and each is different:
> 
> - Docker images:  we have already discussed the lack of need to back
> these up
> - Socialhelp: we need to back this up, but this really does not need to
> be on btrfs... I will migrate it soon
>  
> 
> 
>     Another concern: creating multiple btrfs volumes on top of MD and LVM is
>     probably stupid: btrfs is complicated also because it handles raid and
>     subvolumes at higher level. If we decide to deploy lots of containers on
>     freedom, we should probably rethink the disk layout.
> 
> 
> I don't think we need to, we only really need to have 1 btrfs partition
> - the docker image store.  I think that the overhead on that partition
> won't fill up the rest of the disk space =)
> 
> 
> What's your opinion on this?

Agree with you.

Today I spoke with Teo T'so of ext4 fame. He told me that he'd use
overlayfs, but it's still new and immature and anyway we don't have a
recent enough kernel for it.

Wow, this entire software stack seems pretty cutting edge! I'm 100%
happy to experiment, but we should hold back on migrating anything
critical until the dust settles a bit more.

-- 
 _ // Bernie Innocenti
 \X/  http://codewiz.org