Date: Thu, 28 Aug 2003 05:57:00 -0700 (PDT) From: Jason Stone <freebsd-current@dfmm.org> To: freebsd-current@freebsd.org Subject: Re: nfs tranfers hang in state getblck or nfsread Message-ID: <20030828055145.P3417@walter> In-Reply-To: <3F4DCBB1.2BDA25AC@mindspring.com> References: <Pine.NEB.3.96L.1030827090202.23748B-100000@fledge.watson.org> <20030827211535.N3417@walter> <3F4DCBB1.2BDA25AC@mindspring.com>
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-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 > > I'm also seeing a similar problem - I have a cluster of high-volume > > mailservers delivering mail over nfs to maildirs on a netapp. The cluster > > was all 4-stable, but I decided to mix a couple of 5.1 boxes in to see how > > they would do. [...] > > My mounts are all nfsv3 over udp. > > UDP has problems, if you lose any packets at all. The problem is that > the packet reassembly buffer stays full until you retry, and the retry > is out of band, for packets larger than the MTU size. > > What happens when you drop the read and write size low enough that the > data and headers fit in a single UDP packet (e.g. according to > "tcpdump")? Does it "suddenly" become more reliable? I'll try to play around with it and see. We actually had this discussion already over on -performance (and I get what you're saying), but the interesting question here is, why is 5.1 behaving so differently from 4-stable on identical hardware under identical load. -Jason -------------------------------------------------------------------------- Freud himself was a bit of a cold fish, and one cannot avoid the suspicion that he was insufficiently fondled when he was an infant. -- Ashley Montagu -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.1 (FreeBSD) Comment: See https://private.idealab.com/public/jason/jason.gpg iD8DBQE/TfwcswXMWWtptckRAoZIAKCA6doHe3VXrwFj/xX/HkfV18emYACfW1GK Yw5ZniWoHqHQg/ez8sj4Svc= =hFfm -----END PGP SIGNATURE-----
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