From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from pigeon.gentoo.org ([69.77.167.62] helo=lists.gentoo.org) by finch.gentoo.org with esmtp (Exim 4.60) (envelope-from ) id 1KswDw-0006oS-Om for garchives@archives.gentoo.org; Thu, 23 Oct 2008 09:11:20 +0000 Received: from pigeon.gentoo.org (localhost [127.0.0.1]) by pigeon.gentoo.org (Postfix) with SMTP id 276AAE033A; Thu, 23 Oct 2008 09:11:19 +0000 (UTC) Received: from mail00.xencon.net (mail00.xencon.net [83.246.72.66]) by pigeon.gentoo.org (Postfix) with ESMTP id D8996E033A for ; Thu, 23 Oct 2008 09:11:18 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by mail00.xencon.net (Postfix) with ESMTP id 7AA5C81AB07 for ; Thu, 23 Oct 2008 10:57:51 +0200 (CEST) X-Virus-Scanned: amavisd-new 2.4.4 (20061120) at xencon.net X-Spam-Score: -2.334 X-Spam-Level: X-Spam-Status: No, score=-2.334 required=4.5 tests=[ALL_TRUSTED=-1.8, AWL=-1.307, BAYES_20=-0.74, DNS_FROM_SECURITYSAGE=1.513] Received: from mail00.xencon.net ([127.0.0.1]) by localhost (mail00.xencon.net [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id ySZoFA+isNMC for ; Thu, 23 Oct 2008 10:57:51 +0200 (CEST) Received: from [10.2.10.253] (unknown [81.14.211.35]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) (Authenticated sender: modelnine) by mail00.xencon.net (Postfix) with ESMTP id 1D37881AB01 for ; Thu, 23 Oct 2008 10:57:51 +0200 (CEST) From: Heiko Wundram Organization: Gehrkens.IT - x|encon To: gentoo-user@lists.gentoo.org Subject: Re: [gentoo-user] md-device too small: where's my mistake? Date: Thu, 23 Oct 2008 11:11:12 +0200 User-Agent: KMail/1.9.10 References: <48FF3194.7020809@xunil.at> In-Reply-To: <48FF3194.7020809@xunil.at> Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-Id: Gentoo Linux mail X-BeenThere: gentoo-user@lists.gentoo.org Reply-to: gentoo-user@lists.gentoo.org MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Content-Disposition: inline Message-Id: <200810231111.12539.heiko@xencon.net> X-Archives-Salt: 6a3e7a97-3815-40c0-bde6-08e4c7eff84f X-Archives-Hash: 219d7975c6ca57f7dd79ac3d41893e43 Am Wednesday 22 October 2008 15:58:44 schrieb Stefan G. Weichinger: > md2 is the one that gives me headaches. AFAI understand it should be > about 3TB in size, but it is only 774 GB .... > > # fdisk -l /dev/md2 > > Platte /dev/md2: 774.0 GByte, 774044975104 Byte > 2 K=F6pfe, 4 Sektoren/Spuren, 188975824 Zylinder > Einheiten =3D Zylinder von 8 =D7 512 =3D 4096 Bytes > Disk identifier: 0x00000000 > > > Why? You cannot manage disks >=3D ~2TB with fdisk (i.e., DOS partition tables), = as=20 they (or rather the on-disk-structure of DOS partition tables) have an=20 inherent limitation in the maximum number of LBA48-blocks they can address. I'd presume that because of this inherent limitation, fdisk is reporting th= e=20 wrong total size (2TB+774G+epsilon ~ 3TB; sounds like somewhere someone is= =20 doing a modulo operation, possibly), and completely "off" values for=20 heads/sectors. Anyway, md-devices cannot be partitioned anyway (of course you can write a= =20 partition table on them, but the kernel won't use that to create md2-1,-2,= =20 etc.), so using fdisk is wrong. If you want to check the "real" size of the device, don't use fdisk, but=20 rather use blockdev --getsize64 /dev/md2 which shows you the byte-count of the corresponding volume, and which I thi= nk=20 will be 3TB, as you want it to be. If you want to subpartition large devices, use lvm(2), which does not have = the=20 2TB limitation on size. Hope this helps! =2D-=20 Heiko Wundram hackerkey://v4sw7CHJLSUY$hw5ln5pr7FOP$ck2ma9u7FL$w3DVWXm0l7GL$i65e6t3EMRSXb= 7ADORen5a26s5MSr2p-6.62/-6.56g5AORZ