Re: [LSF/MM/BPF TOPIC] A block level, active-active replication solution

[Philipp Reisner <philipp.reisner@linbit.com>]

Am Tue, Feb 03, 2026 at 04:09:59PM +0100 schrieb Haris Iqbal:
> Hi Haris,
> 
> We are working on a pair of kernel modules which would offer a new
> replication solution in the Linux kernel. It would be a block level,
> active-active replication solution for RDMA transport.
> 
> The existing block level replication solution in the Linux kernel is
> DRBD, which is an active-passive solution. The data replication in
> DRBD happens through 2 network hops.
>
>
> An active-active solution which one can build is by exporting block
> devices, either through NVMeOF or RNBD/RTRS, over the network, and
> then creating a raid1 device over it. It would provide a single hop
> replication solution, but the synchronization during a degraded state
> goes through 2 hops.
> 
> The proposed solution would provide an active-active single hop
> replication, and a single hop synchronization (directly between
> storage nodes) in case of a degraded state.
[...]


I stumbled across this post because of the newer replies.

I want to point out that we have significantly developed DRBD over the
last 15 Years as an out-of-tree module. In the past months, we began
the process of getting all those improvements back into Linux
upstream.

With that, DRBD9 became multi-node. It does the “active-active single
hop replication” as it is. The networking part is now abstracted into
transport modules. We have one for TCP, one for load balancing across
multiple TCP connections, and one for RDMA.

What you are doing here, in DRBD lingo, is a diskless primary
connected to multiple storage nodes.

Find everything here https://github.com/LINBIT.
The latest edition of what we bring to the upstreaming discussion:
https://github.com/LINBIT/linux-drbd/tree/drbd-next

Philipp