On Thu, Oct 31, 2013 at 10:45:46AM -0400, Michael Richardson wrote: > > >> I am chasing a NFS server performance issue on Ubuntu > >> 3.8.13-030813-generic kernel. We setup 32 NFSD threads on our NFS > >> server. > > I have been also trying to figure out NFS performance issues at my home > office. Server is ubuntu precise (3.2.0-55, old, true) kernel, and clients > are mostly a mix of Debian versions (mostly virtualized XEN). > GbE over a VLAN is setup just for storage, and mostly IPv6 connections. > > J. Bruce Fields <bfields@xxxxxxxxxxxx> wrote: > > Would you be willing to test an upstream kernel and/or some patches? > > Sounds like you're using only NFSv4? > > I'm also willing to; my preference would be to build a generic 3.10 or 3.11 > kernel with NFS as a module, and then update the NFS code, but I > haven't gotten around to scheduling some time to reboot a bunch. > > What I observe is huge TCP send queues on the server and what appears to be > head of queue blocking on the client. This looks like a client issue to me, > and for at least one client (my mpd/shoutcast server), I'm happy to reboot > it regularly... I notice the NFS delays because the music stops :-) > > There are some potential instabilities in frequency of IPv6 Router > Advertisements due to a bug in the CeroWRT, which initially I was blaming, > but I'm no longer convinced, since it happens over IPv4 on the storage VLAN > too. > > Shyam, please share with me your testing strategy. Your problem sounds different; among other things, it's with reads rather than writes. Yes, testing with a recent upstream kernel would be a good start. 3.11 or more recent would be ideal as there was a fix for read deadlocks there (which I doubt you're hitting, but would be nice to rule it out). --b. -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
