From owner-freebsd-geom@FreeBSD.ORG Sun Jul 9 15:58:32 2006 Return-Path: X-Original-To: freebsd-geom@freebsd.org Delivered-To: freebsd-geom@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id DDB0816A4DF for ; Sun, 9 Jul 2006 15:58:32 +0000 (UTC) (envelope-from fb-geom@psconsult.nl) Received: from ps226.psconsult.nl (ps226.psconsult.nl [213.222.19.226]) by mx1.FreeBSD.org (Postfix) with ESMTP id 6051743D6E for ; Sun, 9 Jul 2006 15:58:27 +0000 (GMT) (envelope-from fb-geom@psconsult.nl) Received: from phuket.psconsult.nl (localhost [127.0.0.1]) by phuket.psconsult.nl (8.13.1/8.13.1) with ESMTP id k69Fw0xp067842 for ; Sun, 9 Jul 2006 17:58:00 +0200 (CEST) (envelope-from fb-geom@psconsult.nl) Received: (from paul@localhost) by phuket.psconsult.nl (8.13.1/8.13.1/Submit) id k69FvxJj067841 for freebsd-geom@freebsd.org; Sun, 9 Jul 2006 17:57:59 +0200 (CEST) (envelope-from fb-geom@psconsult.nl) X-Authentication-Warning: phuket.psconsult.nl: paul set sender to fb-geom@psconsult.nl using -f Date: Sun, 9 Jul 2006 17:57:59 +0200 From: Paul Schenkeveld To: freebsd-geom@freebsd.org Message-ID: <20060709155759.GA67709@psconsult.nl> Mail-Followup-To: freebsd-geom@freebsd.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.6i Subject: Which geom to use? X-BeenThere: freebsd-geom@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: GEOM-specific discussions and implementations List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 09 Jul 2006 15:58:32 -0000 Hi, Some installations just need a lot of filesystems (e.g. systems with many jails) making geom_bsd a bad choice because it only supports 7 partitions. So far I've been using vinum and gvinum for the task of dividing my disk which is also quite convinient for adding new partitions in so far unallocated space later on. On systems with mirrored disks (or RAID5) this works fine but on systems with a single disk this approach has a very bad consequence: when a disk error occurs anywhere on the disk, all subdisk and thus all volumes on this drive object become invalid and the system crashes. Another approach is to slice up the disk in MBR and divide each slice in 7 patitions with bsdlabel giving you 28 partitions to use and less freedom to re-allocate later on because it's a very hard job to change the MBR slices without doing a complete re-partitioning. I've heard of people putting filesystems in files using md(4) but I fear the performance penalty of going through a filesystem layer twice. So what would you guys recommend in this case, gpt(4)? Or is there some kind of geom that does just the volume management of gvinum without marking all volumes down at the first media error? Regards, Paul Schenkeveld