From owner-freebsd-hackers@FreeBSD.ORG Sat Jan 23 15:11:19 2010 Return-Path: Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id A9A501065679 for ; Sat, 23 Jan 2010 15:11:19 +0000 (UTC) (envelope-from jhellenthal@gmail.com) Received: from qw-out-2122.google.com (qw-out-2122.google.com [74.125.92.26]) by mx1.freebsd.org (Postfix) with ESMTP id 568CB8FC1C for ; Sat, 23 Jan 2010 15:11:19 +0000 (UTC) Received: by qw-out-2122.google.com with SMTP id 5so531953qwd.7 for ; Sat, 23 Jan 2010 07:11:18 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:sender:date:from:to:cc :subject:in-reply-to:message-id:references:user-agent :x-openpgp-key-id:x-openpgp-key-fingerprint:mime-version :content-type; bh=Ur6a2Wr98dbHy6HuS3bKdkBHku3qHNMKvs0ptCbrHco=; b=Lq1yXBXdTJOsfqn5AIei8MjeYsAkVAIvZqVVyHDOBjbq+Y4DZJExoXu2i7cqGoZA4X nVfKfiBqf0avRt6MBMXMCv3GMvR951h4c9jF0wclemP3toQmG2rho4RSWgvn24AVJrLa YuHd+sZMP7hgVIzJsx/II+VutdsNVrsJh6jd4= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=sender:date:from:to:cc:subject:in-reply-to:message-id:references :user-agent:x-openpgp-key-id:x-openpgp-key-fingerprint:mime-version :content-type; b=f5D3hQskpQzh3258MV/c7RBNW+RhstltiK9JtvkFR7IHUWC9F67iI7pdiJeFu73s22 IA8MBhAmJ9ezNrOPT5FjomY5dSUywwdYf/b6FVzZqzB/gxgEGNjDP9Iz3BHxl5q2x+Pb qrexb19fjh3ykAZF4+ajTiWj5zi0rkEeQg7FI= Received: by 10.224.106.80 with SMTP id w16mr2813159qao.362.1264259478320; Sat, 23 Jan 2010 07:11:18 -0800 (PST) Received: from centel.dataix.local (ppp-21.26.dialinfree.com [209.172.21.26]) by mx.google.com with ESMTPS id 8sm11346601qwj.23.2010.01.23.07.11.13 (version=TLSv1/SSLv3 cipher=RC4-MD5); Sat, 23 Jan 2010 07:11:17 -0800 (PST) Sender: "J. Hellenthal" Date: Sat, 23 Jan 2010 10:10:54 -0500 From: jhell To: Alexander Leidinger In-Reply-To: <20100123102513.00001f67@unknown> Message-ID: References: <7f14551c1001190119x46c6b04dx2362cd1252f0d81@mail.gmail.com> <7f14551c1001190216w49814186n1ada2b721380502b@mail.gmail.com> <4B55C5A6.2020109@DataIX.net> <20100120111433.25801pnmhrxnirok@webmail.leidinger.net> <20100123102513.00001f67@unknown> User-Agent: Alpine 2.00 (BSF 1167 2008-08-23) X-OpenPGP-Key-Id: 0x89D8547E X-OpenPGP-Key-Fingerprint: 85EF E26B 07BB 3777 76BE B12A 9057 8789 89D8 547E MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed Cc: FreeBSD Hackers , Artem Belevich Subject: Re: Setting "zfs_arc_max" value in FreeBSD 8. X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 23 Jan 2010 15:11:19 -0000 On Sat, 23 Jan 2010 04:25, Alexander@ wrote: > On Fri, 22 Jan 2010 21:39:48 -0500 jhell wrote: > >> >> On Fri, 22 Jan 2010 11:47, fbsdlist@ wrote: >>>>> Anyone know if it is adjustable on a system with 1024MB of ram ? >>>>> Is this just being auto calculated by some other value ? >>> >>> You may want to make sure that vm.kmem_size is set to a value much >>> larger than vfs.zfs.arc_max. Default value may be too small to allow >>> such a large ARC. >>> >>> On a side note, I'm not sure that ZFS is a good match for system >>> with only 1G of RAM. By trial and error on my box with 8G or memory >>> I've figured out that I need to set arc_max ~1G below physical >>> memory size to avoid lockups under load. YMMV. >>> >> >> ZFS on this box with 1G has been quite enjoyable actually. With the >> settings I have posted I have not had any lockup on stable/7 and no >> sudden freezes or waits for transfers. So this entirely thus far has >> been a godsend. I had even put this thing through some of the >> tortures that others have posted to the list and not come up with the >> same results but better. There is obviously a lot of variables in >> this between hardware and configurations used so the results are >> minimal in comparison. With ZFS in place on this machine it performs >> a little bit under specs for the hardware but I wouldn't expect >> anything less for such a file-system. > > You may want to switch to fletcher4 checksums. This is the default in > Solaris and 8.0 now. I didn't merge this change to 7-stable as I didn't > took the time to analyze if the change for the default has some unwanted > implications for existig pools. > I will do this and report back with any differences that I find. As for your previous email that arrived I believe after this one, Thank you for your replies I appreciate the feedback. > I have a 9-current box with 1GB RAM and ZFS which shows the slow-down > after some hours of running (and doing things) too. It would be good to > make a list of OS versions and if there are slowdowns or not (anyone > with time out there to have a look at the mails and get this info out > of the mails / people?). Maybe it is related to changes not in ZFS... > > Bye, > Alexander. > Is there any recommendations from anyone ? so there is a basis for what can be tested from. (unixbench|iozone|others) in comparison to the same results version to version ? Thanks -- jhell