On Sun, 2012-11-11 at 07:18 -0500, Karsten Suehring wrote: > Package: src:linux > Version: 3.2.32-1 > Severity: important > > I originally niticed the issue on Ubuntu 12.04.1, but could reproduce it on > Debian as well. > > I upgraded a squeeze system to testing and found that NFS access > creates a high load on the NFS server. A single client machine with > a single write causes 40% system load, where the original load on Squeeze > was 7-10% (which still is high, but might be causes by running in a test VM).
I don't think load figures from a VM are likely to be meaningful. [...] > I have played around with different nfs export and mount options. The only > change that I found was using -o proto=uds when mounting. This reduces the > load to 15% which is still higher than the original load, but still much lower > that 40%. > > Ubuntu Bug #879334 and it's duplicates report the same issues. This says the problem was bisected to: commit 9660439861aa8dbd5e2b8087f33e20760c2c9afc Author: Olga Kornievskaia <a...@citi.umich.edu> Date: Tue Oct 21 14:13:47 2008 -0400 svcrpc: take advantage of tcp autotuning so no wonder UDP doesn't suffer as much. (But I can't recommend ever using UDP for NFS.) It also refers to upstream bug <https://bugzilla.kernel.org/show_bug.cgi?id=40912> where the following fix is suggested: > BTW, could you test the latest upstream? This may be fixed by > d10f27a750312ed5638c876e4bd6aa83664cccd8 "svcrpc: fix > svc_xprt_enqueue/svc_recv > busy-looping". [...] That fix was backported into 3.2.29, so we have it already. Are you definitely running the above version (3.2.32-1) on the server? Ben. -- Ben Hutchings Design a system any fool can use, and only a fool will want to use it.
signature.asc
Description: This is a digitally signed message part