From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx3.redhat.com (mx3.redhat.com [172.16.48.32]) by int-mx1.corp.redhat.com (8.13.1/8.13.1) with ESMTP id m3HCk1EI009908 for ; Thu, 17 Apr 2008 08:46:01 -0400 Received: from septimus.inrp.fr (septimus.inrp.fr [193.51.247.28]) by mx3.redhat.com (8.13.8/8.13.8) with ESMTP id m3HCjGn3004243 for ; Thu, 17 Apr 2008 08:45:16 -0400 Received: from septimus.inrp.fr (septimus.inrp.fr [127.0.0.1]) by localhost.septimus.inrp.fr (Postfix) with ESMTP id E97B7E3274 for ; Thu, 17 Apr 2008 14:45:13 +0200 (CEST) Received: from valerian.inrp.fr (valerian.inrp.fr [195.83.134.122]) by septimus.inrp.fr (Postfix) with ESMTP id DC3AFE3273 for ; Thu, 17 Apr 2008 14:45:13 +0200 (CEST) Received: from localhost (localhost.localdomain [127.0.0.1]) by valerian.inrp.fr (Postfix) with ESMTP id CA1062C0E5 for ; Thu, 17 Apr 2008 14:45:13 +0200 (CEST) Received: from valerian.inrp.fr ([127.0.0.1]) by localhost (valerian [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 12816-07 for ; Thu, 17 Apr 2008 14:45:09 +0200 (CEST) Received: from [195.83.134.19] (SCI004.inrp.fr [195.83.134.19]) by valerian.inrp.fr (Postfix) with ESMTP id DE8F32BEAD for ; Thu, 17 Apr 2008 14:45:09 +0200 (CEST) Message-ID: <4807463B.2070508@gmail.com> Date: Thu, 17 Apr 2008 14:44:43 +0200 From: Thomas Bellembois MIME-Version: 1.0 Subject: Re: [linux-lvm] LVM snapshot - "dd" file size References: <48061439.6040001@gmail.com> <20080416210439.GA31820@pretender.frop.net> <003e01c8a009$fa453ad0$0132a8c0@denie> In-Reply-To: <003e01c8a009$fa453ad0$0132a8c0@denie> Content-Transfer-Encoding: 7bit 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" To: LVM general discussion and development Nice tip ! It works fine ! Thanks a lot. Ragards, Thomas Denie Andriessen wrote: > A compressed dd can still be quite large, as there still might contain > non zero values.. > > if you compress the image, a possible way to make the resulting files > smaller is to: > > - do a: 'dd if=/dev/zero of=/dummyfile' on the filesystem first (you > might want to use 'bs' and 'count' parameters) > - if you topped off the disk, delete the all zero dummyfile. > > The zipped result might be smaller. (both with dd and with tar..) > > Regards, > Denie > > ----- Original Message ----- From: > To: "LVM general discussion and development" > Sent: Wednesday, April 16, 2008 11:04 PM > Subject: Re: [linux-lvm] LVM snapshot - "dd" file size > > >> this has nothing to do with LVM. >> >> dd knows nothing about files, it just copies the entire device (or >> file or whatever). >> >> tar will work, if you use the right command line switches. Search >> around on the web for pointers on how to use it. >> >> Another intermediate way would be to compress the image you get with dd. >> >> On Wed, Apr 16, 2008 at 04:59:05PM +0200, Thomas Bellembois wrote: >>> Hi! >>> >>> I am using LVM partitions on a Debian Xen system. >>> I use LVM snapshots to clone and backup my virtual machines. >>> >>> I have noticed that the ISO file created with the "dd" command it much >>> bigger that the partition used space (actually 4.7GB for the ISO - >>> 500MB >>> used space). No problem if I mount the LVM snapshot and "tar" all of >>> the >>> data. >>> >>> I have googled the question and read that "dd" also copy "not used >>> space". >>> Why is the ISO file so big ? Is the "tar" method less safe ? >>> Is there a better solution ? >>> >>> Thanks for your answers. >>> >>> Regards, >>> >>> Thomas >>> >>> >>> >>> _______________________________________________ >>> linux-lvm mailing list >>> linux-lvm@redhat.com >>> https://www.redhat.com/mailman/listinfo/linux-lvm >>> read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/ >> >> _______________________________________________ >> linux-lvm mailing list >> linux-lvm@redhat.com >> https://www.redhat.com/mailman/listinfo/linux-lvm >> read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/ >> > > _______________________________________________ > linux-lvm mailing list > linux-lvm@redhat.com > https://www.redhat.com/mailman/listinfo/linux-lvm > read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/