[Drbd-dev] DRBD Trim/discard

[Eric Wheeler]

Hello all,


We would like to run DRBD backed by thin-provisioned volumes (think ZFS or 
dm-thinp) which require discard support to dereference unused block 
allocations.  (I searched around for DRBD trim/discard support with little 
commentary except the reference [1] below which does not apply to our use 
case.)


Is discard support on the roadmap?

What are the technical considerations for implementation?

I'm guessing this would be a relatively simple patch, just need to add a 
discard flag to the wire protocol and pass that to the backing device 
(after calculating the metadata offset, if any).

If you can comment on the desired implementation of such a feature and 
point me in the right direction I may be able to write a patch and test.

Any help you can offer would be greatly appreciated!

-Eric

[1] http://lists.linbit.com/pipermail/drbd-user/2012-March/017987.html


--
Eric Wheeler
eWheeler Inc.
http://www.globallinuxsecurity.pro/