From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx1.redhat.com (ext-mx08.extmail.prod.ext.phx2.redhat.com [10.5.110.12]) by int-mx03.intmail.prod.int.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id o23AiP4D013049 for ; Wed, 3 Mar 2010 05:44:25 -0500 Received: from smtp-auth.no-ip.com (smtp-auth.no-ip.com [204.16.252.95]) by mx1.redhat.com (8.13.8/8.13.8) with ESMTP id o23AiAmA018376 for ; Wed, 3 Mar 2010 05:44:10 -0500 Received: from [127.0.0.1] (unknown [62.58.16.80]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) (Authenticated sender: simonloewen.com@noip-smtp) by smtp-auth.no-ip.com (Postfix) with ESMTPSA id 75463B4A5EA for ; Wed, 3 Mar 2010 02:44:09 -0800 (PST) Message-ID: <4B8E3D56.50703@klunky.co.uk> Date: Wed, 03 Mar 2010 11:43:34 +0100 From: J4 MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: [linux-lvm] System won't create devices from volume group : advice on dmsetup create command required (or alternative solution) Reply-To: junk4@klunky.co.uk, 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: linux-lvm@redhat.com Dear all, I am moving an LVM between two machines but the new machine won't create the devices. ** Source machines set-up: LVM created on XEN server as one volume group. The Volume Group was then presented to a XEN host via xm block-attach. The XEN host then used fdisk to create two partitions on the new device (/dev/xvdd1 and /dev/xvdd2) [I wish they had not done this!] The devices were removed from the XEN host (xm block detach) and then vgchange -a n mds (mds is the vg) The discs were unpresented from the source machine. ** Target machine set-up: Phsyical server. The discs were presented from the target machine. # pvscan [results as expected] # vgscan Reading all physical volumes. This may take a while... Found volume group "mds" using metadata type lvm2 # vgchange -a y mds # vgdisplay mds --- Volume group --- VG Name mds System ID Format lvm2 Metadata Areas 4 Metadata Sequence No 2 VG Access read/write VG Status resizable MAX LV 0 Cur LV 1 Open LV 0 Max PV 0 Cur PV 4 Act PV 4 VG Size 209.95 GB PE Size 4.00 MB Total PE 53746 Alloc PE / Size 53735 / 209.90 GB Free PE / Size 11 / 44.00 MB VG UUID TnUWZQ-kK5S-iLTR-U0C5-NYHk-96cw-smDLm2 However, the devices are not created: # ls /dev/mapper | grep mds brw------- 1 root root 253, 11 Mar 3 11:17 /dev/mapper/mds-mds # fdisk -l /dev/mds/mds Disk /dev/mds/mds: 225.3 GB, 225380925440 bytes 255 heads, 63 sectors/track, 27401 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Device Boot Start End Blocks Id System /dev/mds/mds1 1 24152 193992907 83 Linux /dev/mds/mds2 24152 27401 26105594 83 Linux # ls -l /dev/mds/mds* lrwxrwxrwx 1 root root 19 Mar 3 11:17 /dev/mds/mds -> /dev/mapper/mds-mds I think that I have to use dmsetup to create the devices: dmsetup create However, I have no idea where to start. I would be very grateful if someone could advice me on how to proceed, because I have a finite time to keep this UAT environment down. Best regards, J.