From owner-freebsd-fs@FreeBSD.ORG Thu Jun 18 08:29:03 2009 Return-Path: Delivered-To: freebsd-fs@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id CDB45106564A; Thu, 18 Jun 2009 08:29:03 +0000 (UTC) (envelope-from petefrench@ticketswitch.com) Received: from constantine.ticketswitch.com (constantine.ticketswitch.com [IPv6:2002:57e0:1d4e:1::3]) by mx1.freebsd.org (Postfix) with ESMTP id 930C28FC28; Thu, 18 Jun 2009 08:29:03 +0000 (UTC) (envelope-from petefrench@ticketswitch.com) Received: from dilbert.rattatosk ([10.64.50.6] helo=dilbert.ticketswitch.com) by constantine.ticketswitch.com with esmtps (TLSv1:AES256-SHA:256) (Exim 4.69 (FreeBSD)) (envelope-from ) id 1MHCzU-0002iw-CZ; Thu, 18 Jun 2009 09:29:00 +0100 Received: from petefrench by dilbert.ticketswitch.com with local (Exim 4.69 (FreeBSD)) (envelope-from ) id 1MHCzU-000HX6-B9; Thu, 18 Jun 2009 09:29:00 +0100 To: dan.naumov@gmail.com, ronald-freebsd8@klop.yi.org In-Reply-To: Message-Id: From: Pete French Date: Thu, 18 Jun 2009 09:29:00 +0100 Cc: freebsd-fs@freebsd.org, freebsd-stable@freebsd.org Subject: Re: ZFS performance on 7.2-release/amd64 low compared to UFS2 + SoftUpdates X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 18 Jun 2009 08:29:04 -0000 > All the ZFS tuning guides for FreeBSD (including one on the FreeBSD > ZFS wiki) have recommended values between 64M and 128M to improve > stability, so that what I went with. How much of my max kmem is it > safe to give to ZFS? If you are on amd64 then don't tune it, it will tune itself. If you are on i386 (or an earlier verions of amd64) then 128M on a 2 gig machine should be OK, assuming you have kmem_size_max set to the full 1500 odd. Those are numbers which come up time and time again - I ran reliably with them for ages, until the latest -STABLE. -pete.