Problem mounting a LVM

To  manually mount a drive that contains a LVM (Logical Volume)
do the following.

lvdisplay

will output info about your logical volume
the important thing to note here is
the line which says VG Name
VG Name               vg_lvm

sometimes you will get a lv status as not available
to make it available type

vgchange -a y

this will activate any LVMS that werent active and make them available.

then to mount the LVM simply type

mount /dev/vg_lvm   /mnt