I have a 220g partition with ubuntu. And a empty partition 100g. How can I expand the partition with ubuntu? I boot from liveCD, start gparted, sgrink 1 partition, and could't expand the 2 partition.
You boot a live Cd as you have, you then have to manage the changes in steps.
Resize (shrink) partition 1 -> apply changes Resize (expand) partition 2.
The only potential complication you might have is if the Ubuntu partition is in an Extended partition . In that event there may be more steps.
Assuming you have Windows on a primary partition, sda1, and Ubuntu on a logical partition , sda5, in an extended partition, sda2 ..
shrink sda1 -> apply changes -> expand sda2 -> apply changes -> expand sda5 -> apply changes.
In order to expand a partition, there must be free space following it. If it is a logical partition ( numbered 5 and up ), then it must be entirely contained within the extended partition, so you have to expand that first.
You can only expand a partition into unallocated space; you cannot expand into an empty partition. You must delete whatever partition - extended or logical - that is adjacent to the partition you want to expand.
Boot from a LiveCD, such as the Ubuntu 11.10 CD. When you get the chance, choose "Try Ubuntu" (you don't want to install it). When it gives you the desktop, open GParted, and you will see the layout of your drives. You said you have two partitions, so one of them will contain your current installation of Ubuntu; the other will be the "empty" 100GB partition.
In order to expand the Ubuntu partition into the "empty" partition, you must first delete the "empty" partition. Right-click in that partition - making very sure you don't choose the Ubuntu partition! - and choose "Delete" from the pop-up menu. Go ahead and hit "Apply." Once the operation has completed, the partition will become grey and will be labelled "Unallocated."
Now you can expand the Ubuntu partition. Right-click on the Ubuntu partition, choose "Resize," and make it as large as you'd like. When you have it as you want it, close that menu then choose "Apply." The operation will begin and it will probably take a minute or two - or more, depending on what it has to do.