[linux-lvm] LVM groups not visible

[J.L. Blom]

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 at 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.

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:
_____________________________________________________
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)
Warning: invalid flag 0x0000 of partition table 4 will be corrected by
w(rite)

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
______________________________________
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,
Can you perhaps shine some light on it?
(sorry for the long mail).
Joep