the problem is also present when vers=3 and vers=2 I think I found the problem, vers=2,udp transfers at 50 MB/s and vers=3,udp transfers at 90 MB/s (when exported async, but when exported sync - the udp mode rates are <5MB/s) all vers in tcp mode are limited to <1MB/s I am afraid running in udp mode, the docs say udp can cause silent data corruption on gigabit links :x but I did take care of the possible problems - reduced the fragmentation time to 2 seconds and enable 9000 mtu with rsize/wsize=8192 I see the data transfer speed in the file manager (worker) -------- Original Message -------- From: bfields@xxxxxxxxxxxx (J. Bruce Fields) To: jhopper@xxxxxxxxxxxxx Cc: linux-nfs@xxxxxxxxxxxxxxx Subject: Re: extremely slow v4 performance on gigabit link Date: Wed, 5 Aug 2015 14:24:00 -0400 > On Wed, Aug 05, 2015 at 07:13:58AM -0400, jhopper@xxxxxxxxxxxxx wrote: > > I have a very slow (less than 1MB/s) performance with nfsv4 TCP, > > How are you measuring this? > > > rsize/wsize have no effect, server is a kernel 3.19 x86 100hz no > > preempt exporting async nfsv4 TCP on nfs-utils 1.2.7, > > The "async" export option isn't normally recommended, though it's > unlikely to have anything to do with this problem. > > > client is a > > kernel 4.1.3 x64 1000hz full preempt with nfs-utils 1.3.2 , physical > > link is 1 gigabit full duplex, I mounted a few cifs shares to check, > > the cifs shares are working at 30 MB/s and higher > > > > is it possible that preempt has an effect on NFS performance ? does > > timeslice have effect on performance ? > > I think those are unlikely to be relevant. > > --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
