Resize:

vgextend vg_name /dev/sdb1

lvcreate -n /dev/VolGroup/lv_pstorage -l 100%FREE

lvresize --size -8G /dev/VolGroup/lv_root
lvresize --size -35G /dev/VolGroup/lv_vz
lvresize --size -5G /dev/VolGroup/lv_pstorage
lvresize --size +5G /dev/VolGroup/lv_vz

lvextend -l +100%FREE /dev/centos/data

(after extend: resize2fs)

Rescue:

Boot your rescue media.
Scan for volume groups:

# lvm vgscan -v

Activate all volume groups:

# lvm vgchange -a y

List logical volumes:

# lvm lvs –all

With this information, and the volumes activated, you should be able to mount the volumes:

# mount /dev/volumegroup/logicalvolume /mountpoint