From owner-freebsd-fs@FreeBSD.ORG Wed Sep 16 00:53:47 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 AF772106566B for ; Wed, 16 Sep 2009 00:53:47 +0000 (UTC) (envelope-from andrew@modulus.org) Received: from email.octopus.com.au (email.octopus.com.au [122.100.2.232]) by mx1.freebsd.org (Postfix) with ESMTP id 70B1F8FC08 for ; Wed, 16 Sep 2009 00:53:46 +0000 (UTC) Received: by email.octopus.com.au (Postfix, from userid 1002) id 3978D17323; Wed, 16 Sep 2009 10:55:21 +1000 (EST) X-Spam-Checker-Version: SpamAssassin 3.2.3 (2007-08-08) on email.octopus.com.au X-Spam-Level: X-Spam-Status: No, score=-1.4 required=10.0 tests=ALL_TRUSTED autolearn=failed version=3.2.3 Received: from [10.1.4.19] (138.21.96.58.static.exetel.com.au [58.96.21.138]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) (Authenticated sender: admin@email.octopus.com.au) by email.octopus.com.au (Postfix) with ESMTP id 203F317DB6; Wed, 16 Sep 2009 10:55:17 +1000 (EST) Message-ID: <4AB03659.9060703@modulus.org> Date: Wed, 16 Sep 2009 10:50:33 +1000 From: Andrew Snow User-Agent: Thunderbird 2.0.0.6 (X11/20070926) MIME-Version: 1.0 To: Zaphod Beeblebrox References: <200909150047.n8F0l0MS096713@freefall.freebsd.org> <5f67a8c40909151138l4c4fcd3cnc31bf3f59a781052@mail.gmail.com> In-Reply-To: <5f67a8c40909151138l4c4fcd3cnc31bf3f59a781052@mail.gmail.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: freebsd-fs@freebsd.org Subject: Re: kern/138790: [zfs] ZFS ceases caching when mem demand is high 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: Wed, 16 Sep 2009 00:53:47 -0000 Zaphod Beeblebrox wrote: > Are we back to the old fight on dividing the system memory resource between > cache and paging again? This seems like a major regression for using ZFS > over UFS. > The idea that this might be happening has caused me to regard my ZFS store > as a largely nfs/smb appliance. > ZFS should be better than that. Why? ZFS is designed for systems with large amounts of memory to spare - I don't think it should be used for any system with less than 2GB. Most brand new systems bought these days will have at least 2GB, if not 4 or 8GB. UFS isn't going away, it is still the filesystem preferred for embedded and low-end systems. - Andrew