From owner-freebsd-fs@FreeBSD.ORG Wed Sep 16 06:35:27 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 0627B1065676 for ; Wed, 16 Sep 2009 06:35:27 +0000 (UTC) (envelope-from zbeeble@gmail.com) Received: from mail-ew0-f208.google.com (mail-ew0-f208.google.com [209.85.219.208]) by mx1.freebsd.org (Postfix) with ESMTP id 7E8568FC17 for ; Wed, 16 Sep 2009 06:35:26 +0000 (UTC) Received: by ewy4 with SMTP id 4so4779358ewy.36 for ; Tue, 15 Sep 2009 23:35:25 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:received:in-reply-to:references :date:message-id:subject:from:to:cc:content-type; bh=H8mQXUw1wUgUGeWtnFGArYHOa+gHvDrvrUjPUvcFZFE=; b=ZG0iXytYMDCXVlOkJp+KgQxDzquulSW/LJVQJTnrMvZ6p+BL6mh87xo4ohWzH98xdM R+eg6Xq7oCmJXoj1Tvy4u7YewS2soqy0xF2s02NtFa6rAlWUxu7irYBsCA0nZUei4anK 9QopWaYHqGJFwuf1iFnAid4Act4LieEw+U/Vo= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type; b=ptVFPGqW5wdqalJZ0b/PJqbO5x05Qop+iHojjq5kYVecmvjyqdFz1y8+MN3AG3TcXl 78K1ZeY0cB5l8D4tcVfBKf2OKZ9HFWTzTu9w+TlsyKbNOtqcbbBEwXe5uqniSlrnN2kG 4HjQpTmpfagudtRi0xR4cGY0zuQRheJlArCIc= MIME-Version: 1.0 Received: by 10.216.17.78 with SMTP id i56mr1961165wei.80.1253082925552; Tue, 15 Sep 2009 23:35:25 -0700 (PDT) In-Reply-To: <4AB03659.9060703@modulus.org> References: <200909150047.n8F0l0MS096713@freefall.freebsd.org> <5f67a8c40909151138l4c4fcd3cnc31bf3f59a781052@mail.gmail.com> <4AB03659.9060703@modulus.org> Date: Wed, 16 Sep 2009 02:35:25 -0400 Message-ID: <5f67a8c40909152335k747dc9eao5d56f3cfdc77d3e4@mail.gmail.com> From: Zaphod Beeblebrox To: Andrew Snow Content-Type: text/plain; charset=ISO-8859-1 X-Content-Filtered-By: Mailman/MimeDel 2.1.5 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 06:35:27 -0000 On Tue, Sep 15, 2009 at 8:50 PM, Andrew Snow wrote: > Zaphod Beeblebrox wrote: > > 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. > I don't see why that has to be the case. ZFS is certainly _tuned_ for large filesystems, but it's feature set has many more uses. Pretty much the entire world got the memo that unified buffercache was good. As I understand the stuff I've read, the fact that ZFS (in FreeBSD) isn't unified is largely due to making it easier to import (sure... fine... but) --- meaning that it's an item that should be fixed. As I understand it, ZFS is unified on OpenSolaris. > UFS isn't going away, it is still the filesystem preferred for embedded and > low-end systems. > What... snapshots are suddenly unhelpful on smaller systems? I think not.