resize ubuntu 12.10 root partition (after resizing virtualbox disk)

resize

$ fdisk /dev/sda

Command (m for help): p

Disk /dev/sda: 137.4 GB, 137438953472 bytes
255 heads, 63 sectors/track, 16709 cylinders, total 268435456 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x0007427a

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *        2048      499711      248832   83  Linux
/dev/sda2          501758    20764671    10131457    5  Extended
/dev/sda5          501760    20764671    10131456   8e  Linux LVM

Command (m for help): d
Partition number (1-5): 5

Command (m for help): d
Partition number (1-5): 2

Command (m for help): n
Partition type:
   p   primary (1 primary, 0 extended, 3 free)
   e   extended
Select (default p): e
Partition number (1-4, default 2): 
Using default value 2
First sector (499712-268435455, default 499712): 
Using default value 499712
Last sector, +sectors or +size{K,M,G} (499712-268435455, default 268435455): 
Using default value 268435455

Command (m for help): n
Partition type:
   p   primary (1 primary, 1 extended, 2 free)
   l   logical (numbered from 5)
Select (default p): l
Adding logical partition 5
First sector (501760-268435455, default 501760): 
Using default value 501760
Last sector, +sectors or +size{K,M,G} (501760-268435455, default 268435455): 
Using default value 268435455

Command (m for help): t
Partition number (1-5): 5
Hex code (type L to list codes): 8e
Changed system type of partition 5 to 8e (Linux LVM)

Command (m for help): w
The partition table has been altered!

Calling ioctl() to re-read partition table.

WARNING: Re-reading the partition table failed with error 16: Device or resource busy.
The kernel still uses the old table. The new table will be used at
the next reboot or after you run partprobe(8) or kpartx(8)
Syncing disks.
$ reboot
$ pvresize /dev/sda5
$ lvresize -l '+100%FREE' /dev/quantal64/root
$ resize2fs -p /dev/quantal64/root
$ reboot

copy-paste-able sudo pvresize /dev/sda5 && sudo lvresize -l '+100%FREE' /dev/quantal64/root && sudo resize2fs -p /dev/quantal64/root