On Fri, 2009-03-13 at 14:32 -0700, David Rees wrote: > On Fri, Mar 13, 2009 at 2:10 PM, Trond Myklebust > <trond.myklebust@xxxxxxxxxx> wrote: > > On Fri, 2009-03-13 at 13:36 -0700, David Rees wrote: > >> Steps to reproduce: > >> > >> 1. Write a big file to the same partition that is exported on the server: > >> dd if=/dev/zero of=/opt/export/bigfile bs=1M count=5000 conv=fdatasync > >> 2. Write a small file to the same partition from the client: > >> dd if=/dev/zero of=/opt/export/bigfile bs=16k count=8 conf=fdatasync > > > > You don't need conv=fdatasync when writing to NFS. The close-to-open > > cache consistency automatically guarantees fdatasync on close(). > > Yeah, I didn't think I did, but I added it for good measure since I > needed it to simulate load directly on the server. It doesn't seem to > affect the numbers significantly either way. > > >> I am seeing slightly less than 2kBps (yes, 1000-2000 bytes per second) > >> from the client while this is happening. > > > > UDP transport, or TCP? If the former, then definitely switch to the > > latter, since you're probably pounding the server with unnecessary RPC > > retries while it is busy with the I/O. > > > > For the same reason, also make sure that -otimeo=600 (the default for > > TCP). > > Yes, both set that way by default. From /proc/mounts on the client: > > rw,vers=3,rsize=1048576,wsize=1048576,namlen=255,hard,nointr,proto=tcp,timeo=600,retrans=2,sec=sys,mountaddr=10.2.1.13,mountvers=3,mountproto=tcp,addr=10.2.1.13 That all looks correct. Just a few more random thoughts: Do you perhaps see a lot of sockets connected to port 2049 and that are not in the TCP_ESTABLISHED state when you do 'netstat -nt' on the server? What is the ratio of 'write' to 'commit' operations when you look at the 'nfsstat -s' output (also on the server)? Trond -- 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
