I successfully resized my centos vdi in virtualbox with command VboxManage.exe modifyhd Centos.vdi --resize 12000 But when i started Centos i got error messages that gnome power manager not been installed correctly, also starting Avahi and postfix daemons failed, and after that i haven't gnome screen at all. How do i could fix the situation?
I rolled back to initial state, before resizing and added a new volume instead, the new Q is how to expand a vg_localhost?
output of vdisplay:
--- Physical volume ---
PV Name /dev/sda2
VG Name vg_localhost
PV Size 8,51 GiB / not usable 3,00 MiB
Allocatable yes (but full)
PE Size 4,00 MiB
Total PE 2178
Free PE 0
Allocated PE 2178
PV UUID Z4g5Cc-
"/dev/sdb2" is a new physical volume of "12,51 GiB"
--- NEW Physical volume ---
PV Name /dev/sdb2
VG Name
PV Size 12,51 GiB
Allocatable NO
PE Size 0
Total PE 0
Free PE 0
Allocated PE 0
PV UUID oDCocH-
I did extension of vg and lvresize but still in trouble
lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sdb 8:16 0 20G 0 disk
├─vg_localhost-lv_root (dm-0) 253:0 0 18G 0 lvm /
└─vg_localhost-lv_swap (dm-1) 253:1 0 2G 0 lvm [SWAP]
sda 8:0 0 9G 0 disk
├─sda1 8:1 0 500M 0 part /boot
└─sda2 8:2 0 8,5G 0 part
sr0 11:0 1 1024M 0 rom
df -h
/dev/mapper/vg_localhost-lv_root
6,5G 6,2G 256M 97% /
tmpfs 499M 200K 499M 1% /dev/shm
/dev/sda1 485M 78M 382M 17% /boot
what am i missed?

fdisk -landdf -h. Also, did you resize the partitions and filesystem(s) accordingly? (modifyhdonly changes the disk size) Are you using LVM or plain parititions? – gertvdijk Dec 19 '12 at 15:00