This article come from TI AM335X Wiki:
If you followed the instructions in this Wiki and created a 40G Ubuntu 10.04 machine, you will find that this is a
good size for the installation of one Sitara SDK and all of its tools. However, there may come a time when you run
out of space in the virtual machine. If you have plenty of hard drive space on the Windows host machine then it is
very easy to expand the drive of the virtual machine.
The instructions here are for VMware player version 3.1.5 and later.
In VMware, before starting the virtual machine, click on "Edit virtual machine settings" and then click "Hard Disk"
on the Hardware tab. In the Utilities menu select "Expand..." and enter a new value for the "Maximum disk size".
Click "Expand" then "Ok" to close the settings menu. Now play the machine as usual.
When the machine boots up, Click System --> Administration --> Disk Utility. This will bring up a view of all the
storage devices on the system. The Hard Drive here should show a value equal to the amount that was just edited in
the machine settings. Click on the Hard Drive and a Volume view should be presented. Here you should see the
original Hard Drive as a formatted ext volume. And you should see an additional "Free" partition that is so far
unformatted. Click on this "Free" partition and then click the "Create Partition" button. Enter a name for this
partition. Now click the "Mount Volume" button. The drive should now show up on the desktop and it is ready to
use for additional data space.
The example below shows a machine that was originally 20G and was expanded to 30G. This creates a new 10G partition.
Below methions is to expend a sector onoriginally disk in Ubuntu. for example Ubuntu system is at sda1, expend sector is sda2.
Note: Disk tools is at Apllications->System tools->Preferences in Ubuntu12.04 version. You can add a disk files then use this tools to partitions disk instead of fdisk command. I use it usually.