On Mon, 27 Jul 2009 at 01:19, Ron Johnson wrote: > Now you're getting beyond my pay grade. Do you accept virtual beer cans? :-) > But with uuidgen and tune2fs, you could give sdc1 a new UUID. That would hose > lvm, though, and you'd have to do surgery in /etc/lvm. Hm, tune2fs operates on (filesystem-)superblock, IIRC. I'm still tempted to do "pvcreate" on one of the discs, but I need to find out how much bytes I have to backup so I can restore if something goes wrong. > I'd go the safe/sure route and backup sdc2 if possible Well, I've backup up everything on vg02, but te restore would take a few days. Not that it's a production setup, but I still want to avoid this scenario. > (have you written anything new to it since breaking the mirror?), Yes. > and start over, dropping it from lvm. refdisking it (is there such a > word?), etc, etc. I'm trying to reproduce what happened on a test system, but I think I still fail to understand where LVM looks for "possible PVs to use". I tried something in a Xen DomU # mdadm --create /dev/md0 [...] /dev/loop0 /dev/loop1 # pvcreate /dev/md0 # pvs PV VG Fmt Attr PSize PFree /dev/md0 lvm2 -- 99.94M 99.94M # blkid | egrep 'md|loop' /dev/loop0: UUID="xyIqqj-gOCa-nMzi-Dn4e-swIL-7ZFG-fuwhBf" TYPE="LVM2_member" /dev/loop1: UUID="xyIqqj-gOCa-nMzi-Dn4e-swIL-7ZFG-fuwhBf" TYPE="LVM2_member" /dev/md0: UUID="xyIqqj-gOCa-nMzi-Dn4e-swIL-7ZFG-fuwhBf" TYPE="LVM2_member" Of course, "pvs" still lists only /dev/md0 as an available PV, despite both loop0 and loop1 are available to the system - unlike sdb and sdc when my mirror was still intact. I think it's only a naming issue: my mirrordevice was presented as "sdb" to the system, sdc did not exist yet. Now with the mirror split up, both sdb and sdc show up - and LVM is of course used to sdb. I don't know why LVM bothers with sdc at all, though. In the test system I do: # mdadm --stop /dev/md0 # pvs [nothing] # ln -s /dev/loop0 /dev/md0 # pvs PV VG Fmt Attr PSize PFree /dev/md0 lvm2 -- 99.94M 99.94M :-) ...anyway, I try to backup the LVM header in the test box and see how it goes. Thanks, Christian. -- BOFH excuse #188: ..disk or the processor is on fire. _______________________________________________ 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/
