On Friday 10 November 2006 09:00am, J.L. Blom wrote: > On Fri, 2006-11-10 at 09:27 -0600, Jonathan E Brassow wrote: > > I can't imagine putting LVM on a USB drive... Are you sure LVM is even > > involved here? > > > > You can type 'mount' or 'df' at the command prompt. That will tell you > > how the usbdisk is mounted. If it is mounted from /dev/sda1 - then > > there is no LVM in the mix. > > > > brassow > > Jonathan, > Thanks for your reply. > I didn't know that an USB disk couldn't be used for logical volumes as > pvcreate and lvcreate did not complain. > However, when I now do a lvscan it gives me: > _______________________________________ > [root@laguna ~]# lvscan > Couldn't find device with uuid > 'G6vIxd-bp54-0zd0-PKzf-WI31-xPmr-qoeFAT'. > Couldn't find all physical volumes for volume group VolGroup00. > Couldn't find device with uuid > 'G6vIxd-bp54-0zd0-PKzf-WI31-xPmr-qoeFAT'. > Couldn't find all physical volumes for volume group VolGroup00. > Volume group "VolGroup00" not found > ACTIVE '/dev/VolGroup01/LogVol00' [9.75 GB] inherit > ACTIVE '/dev/VolGroup01/LogVol02' [9.75 GB] inherit > ACTIVE '/dev/VolGroup01/LogVol03' [4.88 GB] inherit > ACTIVE '/dev/VolGroup01/LogVol04' [9.75 GB] inherit > ACTIVE '/dev/VolGroup01/LogVol05' [9.75 GB] inherit > ACTIVE '/dev/VolGroup01/LogVol01' [9.75 GB] inherit > _________________________________________________________________ > As VolGroup00 is on the USB disk which I just had connected. Looks like the USB device wasn't plugged in when the box was booted, perhaps? > df gives: > _____________________________________ > /dev/mapper/VolGroup01-LogVol00 > 9903432 1035860 8356392 12% / > /dev/hda1 99043 25640 68289 28% /boot > tmpfs 512492 0 512492 0% /dev/shm > /dev/mapper/VolGroup01-LogVol02 > 9903432 1789628 7602624 20% /home > /dev/mapper/VolGroup01-LogVol03 > 4951688 4137648 558452 89% /usr > /dev/mapper/VolGroup01-LogVol04 > 9903432 342224 9050028 4% /usr/local > /dev/mapper/VolGroup01-LogVol05 > 9903432 761312 8630940 9% /var > > /dev/sda1 240362656 38037368 190115488 17% /media/disk > ___________________________________________________ > > and fdisk says: Next time, try running "fdisk -l /dev/sda" (or just "fdisk -l" to see all of them). > _____________________________________________________ > The number of cylinders for this disk is set to 30400. > There is nothing wrong with that, but this is larger than 1024, > and could in certain setups cause problems with: > 1) software that runs at boot time (e.g., old versions of LILO) > 2) booting and partitioning software from other OSs > (e.g., DOS FDISK, OS/2 FDISK) Standard thing to see. It's a mostly stupid warning these days, as every desktop & notebook motherboard made in the past 8 years (or so) has LBA support out of the box, so it isn't an issue. In other words, you can just ignore that. > Warning: invalid flag 0x0000 of partition table 4 will be corrected by > w(rite) That sometimes happens when the partition table was initially created by some other tool (like Windows, or Partition Magic), as they don't all do exactly the same thing with some parts of it. Given that the "offending" flag's value was 0x0000, I think it be that it was just never set by the other tool. However, that's not why this is happening in this case (read the next bit to see what's up). > Command (m for help): p > > Disk /dev/sda1: 250.0 GB, 250056705024 bytes > 255 heads, 63 sectors/track, 30400 cylinders > Units = cylinders of 16065 * 512 = 8225280 bytes > > Device Boot Start End Blocks Id System > > Command (m for help): q This is blank because you are trying to read a partition table from the 1st partition. You ran "fdisk /dev/sda1" not "fdisk /dev/sda" as it should have been. I hate it when I do that :) . > ______________________________________ > So I'm at a loss how this is possible. The disk can be reached but > neither lvm nor fdisk can tell me what's on the disk, Since it's a USB disk, I would guess that it wasn't inserted when you booted your box. So, when LVM was being set up by /etc/rc.sysinit, it didn't find that device. If you did another "pvscan" after inserting the USB disk, it might find it. I already covered the problem with fdisk. > Can you perhaps shine some light on it? OK. Overall, I wouldn't bother trying to use LVM with a removable drive (USB/Firewire hard drives, keychain drives, etc.). I can think of one possibly viable way of doing it, but I still probably wouldn't even in that case, because it wouldn't really give you any benefits. So, if you have already included the USB drive into your VG(s), get everything plugged in, make sure pvdisplay, vgdisplay, lvscan and friends are all happy, then run "pvmove /dev/sda1". This will move any data you may have on there to other drives (the one built in to your box). In this thread, everyone has been *assuming* that your USB disk is /dev/sda. If your main hard drive is SATA or SCSI, it very well could be /dev/sda and your USB drive could be /dev/sdb or some other device; i.e., the last letter in the device name could be 'a', 'b', 'c', etc. Run "fdisk -l" to see a list of all the hard drives your system currently sees without the USB drive plugged in, then plug it in and re-run "fdisk -l" and the extra one the second time is your USB drive. Make sure you use the correct device name in your pvmove command. Once the pvmove command is finished, you can safely "redo" your USB device. If it's a hard drive, format it with ext3 or reiserfs or jfs or xfs (as you prefer). If it's a flash device, I would recommend that you look at using JFFS2 for the filesystem. Either way, make sure that the "type" (i.e. System ID) of the partition on your USB device is "83" (for regular Linux filesystems) and not "8e" (which is for Linux LVM PVs). > (sorry for the long mail). np. HTH. [snip] -- Lamont Peterson <peregrine@OpenBrainstem.net> Founder [ http://blog.OpenBrainstem.net/peregrine/ ] GPG Key fingerprint: 0E35 93C5 4249 49F0 EC7B 4DDD BE46 4732 6460 CCB5 ___ ____ _ _ / _ \ _ __ ___ _ __ | __ ) _ __ __ _(_)_ __ ___| |_ ___ _ __ ___ | | | | '_ \ / _ \ '_ \| _ \| '__/ _` | | '_ \/ __| __/ _ \ '_ ` _ \ | |_| | |_) | __/ | | | |_) | | | (_| | | | | \__ \ || __/ | | | | | \___/| .__/ \___|_| |_|____/|_| \__,_|_|_| |_|___/\__\___|_| |_| |_| |_| Intelligent Open Source Software Engineering [ http://www.OpenBrainstem.net/ ]
Attachment:
pgpZU2mxmhi9h.pgp
Description: PGP signature
_______________________________________________ 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/
