Date: Wed, 7 Sep 2011 19:13:30 -0400 (EDT) From: Rick Macklem <rmacklem@uoguelph.ca> To: David Brodbeck <brodbd@uw.edu> Cc: freebsd-fs@freebsd.org Subject: Re: Slow NFSv4 performance, was: Re: ZFSv28+NFSv4 poor file creation performance, "sync=disabled" has no effect Message-ID: <12598691.949771.1315437210575.JavaMail.root@erie.cs.uoguelph.ca> In-Reply-To: <CAHHaOuYda8S09E89jhWV4mE6r8_gnQhr_jn%2BDqM%2B0PeNnUSpqw@mail.gmail.com>
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David Brodbeck wrote: > On Mon, Sep 5, 2011 at 2:16 AM, Pawel Jakub Dawidek <pjd@freebsd.org> > wrote: > > > It would be good if you could try your test on FreeBSD directly. > > This > > way we could see if ZFS is to blame or NFS. > > > > Okay, it appears it is in fact an NFSv4 problem, and I've been barking > up > the wrong tree. I shared out an NFSv4 mountpoint with a UFS ramdisk as > the > backing store, and I got the same slow results. I was fooled by the > fact > that the numbers were similar to what I got using OpenSolaris with the > ZIL > enabled. (This is what I get for making assumptions.) > > Interestingly enough, if I use NFSv3 instead of NFSv4, performance > increases > dramatically. > Oops, it turned out that the 121 Opens for Fedora15 NFSv4 was because I had delegations enabled on the server (which is not the default). When I disabled that, I saw 61 Opens, just like the FreeBSD client and as I would have expected. So, the # of Opens is not the issue. Looking at the packet trace, I did notice that the Open compound is rather complex. It includes the following Ops: PUTFH SAVEFH OPEN GETFH GETATTR RESTOREFH GETATTR (most of these, except SAVEFH/RESTOREFH result in at least one VOP_xxx().) But, I'm afraid that doesn't really help you. Sorry, but no inspiration here, rick ps: Please ignore the last post. It was mostly irrelevant, except that enabling delegations will make it even worse in this case. > It appears it's FreeBSD's NFSv4 server, or the way it's interacting > with > Linux's client, that's the culprit here. I'm not sure if there are > knobs I > should be tweaking to make it perform better; any suggestions on what > to try > next? > > -- > David Brodbeck > System Administrator, Linguistics > University of Washington > _______________________________________________ > freebsd-fs@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-fs > To unsubscribe, send any mail to "freebsd-fs-unsubscribe@freebsd.org"
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