From mboxrd@z Thu Jan 1 00:00:00 1970 From: Philipp Hahn Subject: Re: qcow2 eating up space when formattng Centos Date: Mon, 24 Oct 2011 09:17:14 +0200 Message-ID: <201110240917.18718.hahn@univention.de> References: Mime-Version: 1.0 Content-Type: multipart/signed; boundary="nextPart3517741.ONvppbCxy2"; protocol="application/pgp-signature"; micalg=pgp-sha1 Content-Transfer-Encoding: 7bit Cc: kvm@vger.kernel.org To: day knight Return-path: Received: from mail.univention.de ([82.198.197.8]:1271 "EHLO mail.univention.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753326Ab1JXH0w (ORCPT ); Mon, 24 Oct 2011 03:26:52 -0400 In-Reply-To: Sender: kvm-owner@vger.kernel.org List-ID: --nextPart3517741.ONvppbCxy2 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Content-Disposition: inline Hello Anonnymous, On Monday 24 October 2011 03:22:15 day knight wrote: > I am not sure if this is the right behaviour but qcow2 image seems to > grow when Centos is only formatting the image. I mean it goes upto 30 > Gig once evrything is formatted and installed and it is minimal Centos > install with no gui or apps just baseline. > > OS =3D Centos5 > Virtualization: KVM > Total Qcow2 Image Created =3D 1TB > > Once Centos is installed the qcow2 image shows as around 30 Gig. I > have done several install and they were all less than 4 gig or even > lesser but this seems to not make sense > > Can someone please explain what is going on? You didn't tell which file system you're using. ext3 needs to initialize it= s=20 meta data (super blocks, inote tables), which are scattered all over the=20 image. Depending on your cluster size fpr the qcow2 file, each (small) writ= e=20 takes the space of a full cluster. Add to that the meta-data needed by qcow= 2=20 itself (a two-level tree), 30 GiB seem to be okay. You might want to try ext4 with "delayed allocation" (IMHO enabled by=20 default), which doesn't write all over the range, since initialization of t= he=20 superblock and inode tables is delayed until they are acually needed. Sincerely Philipp =2D-=20 Philipp Hahn Open Source Software Engineer hahn@univention.de Univention GmbH Linux for Your Business fon: +49 421 22 232- 0 Mary-Somerville-Str.1 D-28359 Bremen fax: +49 421 22 232-99 http://www.univention.de/ --nextPart3517741.ONvppbCxy2 Content-Type: application/pgp-signature; name=signature.asc Content-Description: This is a digitally signed message part. -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.9 (GNU/Linux) iEYEABECAAYFAk6lEPoACgkQYPlgoZpUDjkY/QCffDL3ytFh3YmE68qPxDnSQi7w hB8AnA3PKQ5bo3fu1Canq/Bo05/3/eVy =25OQ -----END PGP SIGNATURE----- --nextPart3517741.ONvppbCxy2--