From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from localhost (dhcp-100-19-150.bos.redhat.com [10.16.19.150]) by int-mx09.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id p690pXAG010342 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES128-SHA bits=128 verify=NO) for ; Fri, 8 Jul 2011 20:51:34 -0400 Date: Fri, 8 Jul 2011 20:51:33 -0400 From: Mike Snitzer Message-ID: <20110709005133.GA6588@redhat.com> References: <4E16942E.9070204@tlinx.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: Subject: Re: [linux-lvm] what use is virtualsize -- or how is it to be used? Reply-To: LVM general discussion and development List-Id: LVM general discussion and development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , List-Id: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: LVM general discussion and development On Fri, Jul 08 2011 at 7:17pm -0400, adultsitesoftware@gmail.com wrote: > Virtual size lets you create a 200G file system om a 20G LV and then lvextend as needed, without the need to resize the filesystem. Read about sparse files for ideas of other uses. > > It'd like a sparse device in that blocks need not actually exist until they are written to. > > It currently has a performance and flexibility impact that prevents us from using it, though we would like to. Please have a look at the DM thinp target that was just posted to dm-devel. We don't have lvm2 support for this thinp target yet, we are working on it, but thinp is a much richer solution that should address your needs. Mike