[Gluster-users] Bricks as BTRFS

[Deepak C Shetty]

On 09/25/2014 12:23 PM, Venky Shankar wrote:
> Hey folks,
>
> Wanted to check if anyone out here uses BTRFS (and willing to share 
> their experiences[1]) as the backend filesystem for GlusterFS. We're 
> planning to explore some of it's features and put it to use for 
> GlusterFS. This was discussed briefly during the weekly meeting on 
> #gluster-meeting[2].
>
> To start with, we plan to explore data/metadata checksumming (+ 
> scrubbing) and subvolumes to "offload" the work to BTRFS. The 
> mentioned features would help us with BitRot detection[3] and 
> Openstack Manila use cases respectively (though there are various 
> other nifty things one would want to do with them).

 From openstack Manila perspective, I think this will be useful in the 
following ways:

1) subdir level snapshot can help gluster-nfs driver of Manila and root 
level snap can help gluster native driver of Manila to implement cheap 
(in terms of resources)  snapshot support.
2) Not sure if create from snapshot semantic is supported by btrfs, if 
yes that could be useful too.
3) copy offload if supported
4) data shredding (not sure if btrfs has support for it?)

Also in order for Manila to use/exploit these feature, there must be a 
way to expose these as
capabilities in the gluster cli. That ways openstack ( liek any other 
consumer of gluster) can query for
the capabilities and if present can provide the functionality to the end 
user. So i guess this work should
go along with ability to expose capabilities of the bricks/volume in 
gluster.

My few cents ;-)

thanx,
deepak


>
> Thanks in advance!
>
> [1]: using any of it's features such as snapshot, data/metadata 
> checksumming, etc. as an added functionality for Gluster
> [2]: 
> http://meetbot.fedoraproject.org/gluster-meeting/2014-09-24/gluster-meeting.2014-09-24-12.07.log.html
> [3]: 
> http://www.gluster.org/community/documentation/index.php/Features/BitRot
>
>     Venky