Date: Sun, 9 Feb 2003 18:22:46 -0600 From: Tillman <tillman@seekingfire.com> To: freebsd-questions@FreeBSD.ORG Subject: Re: speeding up NFS Message-ID: <20030209182246.D32740@seekingfire.com> In-Reply-To: <20030209234825.GJ5356@dan.emsphone.com>; from dnelson@allantgroup.com on Sun, Feb 09, 2003 at 05:48:25PM -0600 References: <200302091717.42138.ajacoutot@lphp.org> <20030209192839.GH5356@dan.emsphone.com> <20030209174109.B32740@seekingfire.com> <20030209234825.GJ5356@dan.emsphone.com>
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On Sun, Feb 09, 2003 at 05:48:25PM -0600, Dan Nelson wrote: > In the last episode (Feb 09), Tillman said: > > Which sysctl is this? The closest I can find is: > > > > # sysctl -a | grep nfs | grep sync > > vfs.nfs.async: 0 > > Same one. They split the server sysctls out into nfsrv in 5.*. That makes sense. > > If that's the one, it may still not be necessary. I'm getting about > > 8.5-9 Megabytes/s on NFS reads from a Linux 2.4 client (on a 100Mbit > > switched LAN) with it set to 0, as measured by Bonnie++. This is > > fairly close to the 12MB/s fast ethernet theoretical maximum, so I'm > > happy with performance. > > It only applies to writes. With it set to 0 (the default), FreeBSD > follows the NFS spec and does not return from NFSv2 write or NFSv3 > commit calls without having synced the data to disk. This can slow you > down if you are not on a battery-backed RAID or ramdisk. With NFSv3 > it's not so bad since it supports async client writes (i.e. separate > write and commit calls). When I was benchmarking with bonnie++, I found NFSv2 with async writes turned on to be only marginally faster than v3 with sync'ed commits (under 10% difference). Given the additional safety, I like using sync :-) Thanks for the info, -T -- A man may fight the greatest enemy, take the longest journey, survive the most grievous wound -- and still be helpless in the hands of the woman he loves. - Zensunni Wisdom from the Wandering To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message
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