Date: Sat, 25 Jan 2014 22:13:14 -0500 From: Garrett Wollman <wollman@freebsd.org> To: Rick Macklem <rmacklem@uoguelph.ca> Cc: freebsd-fs@freebsd.org, freebsd-net@freebsd.org Subject: Re: Terrible NFS performance under 9.2-RELEASE? Message-ID: <21220.32074.958702.595502@hergotha.csail.mit.edu> In-Reply-To: <188195924.16327973.1390703786000.JavaMail.root@uoguelph.ca> References: <201401260225.s0Q2PUp1045129@hergotha.csail.mit.edu> <188195924.16327973.1390703786000.JavaMail.root@uoguelph.ca>
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<<On Sat, 25 Jan 2014 21:36:26 -0500 (EST), Rick Macklem <rmacklem@uoguelph.ca> said: > Have you tried increasing readahead by any chance? I think the default > is 1, which means the client will make 2 read requests and then wait for > those replies before doing any more reads. Since you have fast links, > maybe the 2 * 64K reads isn't enough to keep the pipe filled? (This > depends on latency, which you didn't mention.) -o readahead=4 nearly doubles the speed, to a bit over 5 Gbit/s. Oddly, when I unmount the filesystem, the test client sometimes freezes for 15-30 seconds. Since I'm not on the console I can't tell what it's doing when this happens. -GAWollman
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