Thursday, April 29, 2010

Mounting a Linux LVM volume on External harddrive

SkyHi @ Thursday, April 29, 2010
You do not mount a partition of type "Linux LVM" the same way you mount
a partition using a standard Linux file system (e.g. ext2, ext3).





# fdisk -l /dev/hda





Disk /dev/hda: 160.0 GB, 160041885696 bytes


255 heads, 63 sectors/track, 19457 cylinders


Units = cylinders of 16065 * 512 = 8225280 bytes





   Device
Boot     
Start        
End      Blocks   Id  System



/dev/hda1  
*          
1         
13      104391   83  Linux



/dev/hda2             
14       19457  
156183930   8e  Linux LVM






# mount /dev/hda2 /tmp/mnt


mount: /dev/hda2 already mounted or /tmp/mnt busy





First, let's determine the volume group containing the physical volume /dev/hda2.





# pvs


 
PV        
VG         Fmt  Attr
PSize   PFree



  /dev/hda2  VolGroup01 lvm2 a-   148.94G 32.00M


  /dev/hdb2  VolGroup00 lvm2 a-   114.94G 96.00M





Next, let's list the logical volumes in VolGroup01.





# lvdisplay /dev/VolGroup01


  --- Logical volume ---


  LV Name                /dev/VolGroup01/LogVol00


  VG Name                VolGroup01


  LV
UUID               
zOQogm-G8I7-a4WC-T7KI-AhWe-Ex3Y-JVzFcR



  LV Write Access        read/write


  LV Status              available


  # open                 0


  LV Size                146.97 GB


  Current LE             4703


  Segments               1


  Allocation             inherit


  Read ahead sectors     0


  Block device           253:2


  


  --- Logical volume ---


  LV
Name               
/dev/VolGroup01/LogVol01



  VG Name                VolGroup01


  LV
UUID               
araUBI-4eer-uh5L-Dvnr-3bI6-4gYg-APgYy2



  LV Write Access        read/write


  LV Status              available


  # open                 0


  LV Size                1.94 GB


  Current LE             62


  Segments               1


  Allocation             inherit


  Read ahead sectors     0


  Block device           253:3





The logical volume I would like to "mount" (in purely the computing-related sense) is /dev/VolGroup01/LogVol00. The other logical volume is a swap partition.





# mount /dev/VolGroup01/LogVol00 /tmp/mnt

REFERENCES
http://www.brandonhutchinson.com/Mounting_a_Linux_LVM_volume.html


I've not much experience with LVM, but I did have a similar problem to
you, so here's how I solved it (Ubuntu 7.04 server).



1. Install lvm2:



sudo apt-get install lvm2

sudo cp -r /lib/lvm-200/ /lib/lvm-0



2. Take note of the LV Name for the volume you want to mount from the
output of the following command (/dev/VolGroup00/LogVol00 in my case):



sudo lvdisplay



3. Run the following commands to mount the logical volume:



sudo modprobe dm-mod

sudo vgchange -ay

sudo mkdir /mnt/old_hd

sudo mount /dev/VolGroup00/LogVol00 /mnt/old_hd



Worked for me!

REFERENCES
http://ubuntuforums.org/showthread.php?t=428292