From owner-freebsd-fs@FreeBSD.ORG Tue Nov 20 04:59:39 2012 Return-Path: Delivered-To: freebsd-fs@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id 10F56EC0; Tue, 20 Nov 2012 04:59:39 +0000 (UTC) (envelope-from spork@bway.net) Received: from smtp3.bway.net (smtp3.bway.net [216.220.96.27]) by mx1.freebsd.org (Postfix) with ESMTP id 7B82E8FC08; Tue, 20 Nov 2012 04:59:38 +0000 (UTC) Received: from toasty.sporklab.com (foon.sporktines.com [96.57.144.66]) (using TLSv1 with cipher AES128-SHA (128/128 bits)) (No client certificate requested) (Authenticated sender: spork@bway.net) by smtp3.bway.net (Postfix) with ESMTPSA id 6928E9586D; Mon, 19 Nov 2012 23:59:29 -0500 (EST) References: <57ac1f$gf3rkl@ipmail05.adl6.internode.on.net> <50A31D48.3000700@shatow.net> <57ac1f$gg70bn@ipmail05.adl6.internode.on.net> In-Reply-To: Mime-Version: 1.0 (Apple Message framework v1084) Content-Type: text/plain; charset=us-ascii Message-Id: <48C81451-B9E7-44B5-8B8A-ED4B1D464EC6@bway.net> Content-Transfer-Encoding: 7bit From: Charles Sprickman Subject: Re: ZFS FAQ (Was: SSD recommendations for ZFS cache/log) Date: Mon, 19 Nov 2012 23:59:28 -0500 To: Eitan Adler X-Mailer: Apple Mail (2.1084) Cc: FreeBSD FS , Stephen McKay X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 20 Nov 2012 04:59:39 -0000 On Nov 19, 2012, at 11:05 PM, Eitan Adler wrote: > On 16 November 2012 13:41, Eitan Adler wrote: >> On 15 November 2012 23:58, Stephen McKay wrote: >>> On Thursday, 15th November 2012, Eitan Adler wrote: >>> >>>> Can people here please tell me what is wrong in the following content? >>> >>> A few things. I'll intersperse them. >>> >>>> Is there additional data or questions to add? >>> >>> The whole ZFS world desperately needs good documentation. There >>> are misconceptions everywhere. There are good tuning hints and >>> bad (or out of date) ones. Further, it depends on your target >>> application whether the defaults are fairly good or plain suck. >> >> New version of the patch taking into account the comments so far: >> >> http://people.freebsd.org/~eadler/files/add-zfs-faq-section.diff > > Thanks for all the comments, private and public. I've committed a > modified version of the above. Wonderful to see some work on this. One of the great remaining zfs mysteries remains all the tunables that are under "vfs.zfs.*". Obviously there are plenty of read-only items there, but conflicting information gathered from random forum posts and commit messages exist about what exactly one can do regarding tuning beyond arc sizing. If you have any opportunity to work with the people who have ported and are now maintaining zfs, it would be really wonderful to get some feedback from them on what knobs are safe to twiddle and why. I suspect many of the tunable items don't really have meaningful equivalents in Sun's implementation since the way zfs falls under the vfs layer in FreeBSD is so different. Thanks, Charles > > -- > Eitan Adler > Source, Ports, Doc committer > Bugmeister, Ports Security teams > _______________________________________________ > 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"