Mounting LVM logical volumes in break=premount

[Sophie Loewenthal <sophie@klunky.co.uk>]

Hi,

I could not mount some LVM ext4 filesystems on a server earlier this week and was trying to work out what I had to do to make it work.  

I had booted into break=premount ( added to the end of the linux line in Grub ) to fix an error in /etc/fstab that caused root from mounting

I could access volume groups via the LVM command:
%  lvm vgs
VG  #PV #LV #SN Attr   VSize    VFree   
vg0 1   4   0 wz--n-  <99.50g  <28.11g
vg1 1   1   0 wz--n- <500.00g 1020.00m

but when I ran ,
% mount /dev/mapper/vg0-root /tmp/a
I recall a message stating the fs count not be mounted because of wrong file system type.

Did I miss a module that had to be loaded for this to work, or is premount the wrong place to try this?

( In the end I rolled back to a snapshot that worked, but I should know for the future. )

Regards, S
Sent from phone, thus brief