On Tue, Nov 25, 2014 at 02:12:08PM +0100, Paul Bolle wrote:
On Tue, 2014-11-25 at 13:40 +0100, poma wrote:
> On 25.11.2014 11:14, Ian Chapman wrote:
> > Hi,
> > Is anyone successfully running NFS over RDMA on Fedora 20+?
> > I've edited /etc/sysconfig/nfs and set the the following config paramter.
> > RDMA_PORT=20049
> > Upon restarting the nfs server I get the following:
> > modprobe: FATAL: Module svcrdma not found
> > /usr/libexec/nfs-utils/scripts/nfs-server.postconfig: line 12: echo:
> > write error: Protocol not supported
> > So it looks like the kernel module svcrdma is missing and the last
> > kernel to have it was 3.11.10-301.fc20. The postconfig script belongs to
> > nfs-utils.
> > Is svcrdma intentionally not built in the current kernels or has it been
> > replaced by something else?
> [snip unedited copy from someone's terminal]
0) In mainline kernel v3.15 the config option SUNRPC_XPRT_RDMA was split
in two options: SUNRPC_XPRT_RDMA_CLIENT and SUNRPC_XPRT_RDMA_SERVER. See
commit 2e8c12e1b765 ("xprtrdma: add separate Kconfig options for
NFSoRDMA client and server support").
1) Fedora 20 first shipped v3.15 in last July (kernel-3.15.3-200.fc20).
Looking at the git history of the Fedora kernel package I found commit
commit fd469c7db4e6 ("Linux v3.15.2"). It dropped
CONFIG_SUNRPC_XPRT_RDMA=m from the config files (as it was useless). It
set CONFIG_SUNRPC_XPRT_RDMA_CLIENT to 'm' but did not set
CONFIG_SUNRPC_XPRT_RDMA_SERVER. The commit offers no explanation of this
choice. Perhaps it was discusses somewhere else.
2) A similar commit for Rawhide was 700baa35a69e ("Linux
v3.14-12042-g69cd9eba3886"), but it doesn't comment on this choice
3) Perhaps Justin or Josh, authors of those commits, might recall why
only CONFIG_SUNRPC_XPRT_RDMA_CLIENT was set.
At the time, server support for NFSoRDMA wasn't in the greatest shape
and we disabled it at the request of the NFS developers. I believe this
also matches what wound up in RHEL7.
The NFS developers haven't asked us to turn it back on, so it has stayed