Date: Sat, 13 Jul 2013 18:45:40 -0400 (EDT) From: Rick Macklem <rmacklem@uoguelph.ca> To: Berend de Boer <berend@pobox.com> Cc: freebsd-fs <freebsd-fs@freebsd.org> Subject: Re: Terrible NFS4 performance: FreeBSD 9.1 + UFS/ZFS + AWS EC2 Message-ID: <153512858.1034456.1373755540674.JavaMail.root@uoguelph.ca> In-Reply-To: <8761wfvwml.wl%berend@pobox.com>
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Berend de Boer wrote: > >>>>> "Rick" == Rick Macklem <rmacklem@uoguelph.ca> writes: > > Rick> If you could do some testing where you export a UFS volume, > Rick> the results might help to isolate the issue to ZFS vs nfsd. > > Indeed! Have changed subject, as indeed ZFS is a red herring. Issue > shows up with UFS as well. Very high cpu for nfds, about the same > time > to do the operation. > > Tried it with these settings: > > vfs.nfsd.tcphighwater=5000 > vfs.nfsd.tcpcachetimeo=300 > nfs_server_flags="-u -t -n 256" > > > On nfs3 + ufs everything back to normal. I.e. nfs4 was about 15 > minutes, same operation was 241s minutes with nfs3 and nfsd using no > cpu at all basically. > All I can suggest is capturing packets and then emailing be the captured packet trace. You can use tcpdump to do the capture, since wireshark will understand it: # tcpdump -s 0 -w <file>.pcap host <client-host> and then emailing me <file>.pcap. I can take a look at the packet capture and maybe see what is going on. I think you mentioned that you were using a Linux client, but not what version. I'd suggest a recent kernel from kernel.org. (Fedora tracks updates/fixes for NFSv4 pretty closely, so the newest Fedora release should be pretty current.) > Per other reply, tried this too: > > vfs.nfsd.issue_delegations=1 > > Locks up the client at first write access. Ctrl+C doesn't work, need > to explicitly send a KILL signal from other terminal. > > I think it locks up the server in some way as well. Doing an ls on an > exported path locks up. Ctrl+C won't work anymore. Process doesn't > react to any signal. In the end I rebooted the server to get rid of > this. > Obviously broken, but without a lot more information, I can's say anything. (Assuming you can still run commands on the server, you could start with something like "ps axl" and "procstat -kk".) rick > -- > All the best, > > Berend de Boer > > > ------------------------------------------------------ > Awesome Drupal hosting: https://www.xplainhosting.com/ >
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