From owner-freebsd-fs@FreeBSD.ORG Tue Jun 23 12:24:05 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 DE2851065678 for ; Tue, 23 Jun 2009 12:24:05 +0000 (UTC) (envelope-from gary.jennejohn@freenet.de) Received: from mout1.freenet.de (mout1.freenet.de [IPv6:2001:748:100:40::2:3]) by mx1.freebsd.org (Postfix) with ESMTP id 72CC78FC0C for ; Tue, 23 Jun 2009 12:24:05 +0000 (UTC) (envelope-from gary.jennejohn@freenet.de) Received: from [195.4.92.21] (helo=11.mx.freenet.de) by mout1.freenet.de with esmtpa (ID gary.jennejohn@freenet.de) (port 25) (Exim 4.69 #92) id 1MJ52i-0003df-1P; Tue, 23 Jun 2009 14:24:04 +0200 Received: from tc20b.t.pppool.de ([89.55.194.11]:30633 helo=ernst.jennejohn.org) by 11.mx.freenet.de with esmtpa (ID gary.jennejohn@freenet.de) (port 25) (Exim 4.69 #79) id 1MJ52h-0007MR-Lp; Tue, 23 Jun 2009 14:24:04 +0200 Date: Tue, 23 Jun 2009 14:24:02 +0200 From: Gary Jennejohn To: Simun Mikecin Message-ID: <20090623142402.2c8d4b65@ernst.jennejohn.org> In-Reply-To: <288239.1376.qm@web37303.mail.mud.yahoo.com> References: <288239.1376.qm@web37303.mail.mud.yahoo.com> X-Mailer: Claws Mail 3.7.1 (GTK+ 2.16.2; amd64-portbld-freebsd8.0) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: freebsd-fs@freebsd.org Subject: Re: 7.2-STABLE: swap on ZFS v13 X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list Reply-To: gary.jennejohn@freenet.de List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 23 Jun 2009 12:24:06 -0000 On Tue, 23 Jun 2009 03:01:53 -0700 (PDT) Simun Mikecin wrote: > Before ZFS v13 import to the 7-STABLE branch, it was a well known fact that swap on ZFS volume (zvol) will not work. > Recently, I tried to use swap on ZFS v13 (7-STABLE/amd64). It seems that it works. > > I used 4k for the volblocksize as that is equivalent to hardware page size. > I tried with compression enabled and disabled. Enabling compression reduces number of bytes that need to be swapped in and out to the zvol. > > zfs create -o volblocksize=4k -o compression=on -o org.freebsd:swap=on -V 4g tank/swap > swapon /dev/zvol/tank/swap > > Is there anybody else who tried 7-STABLE/amd64 with swap on ZFS v13? Does it work or not? > I doubt that you can generate a crash dump using ZFS as swap, especially if you have compression enabled. But I might be wrong. Does anyone know? --- Gary Jennejohn