I have a system running Ubuntu 13.10 in a single partition. I need to create another ext4 partition, is it possible without reinstalling Ubuntu?
Please show me the procedure, if it is possible.
Yes you can create another ext4 partition from the single Ubuntu partition without reinstalling using Gparted Partition Editor.
For this you have to boot from Ubuntu live disk or Gparted live disk.Please note that you can't able to resize a mounted partition in Gparted.
Follow the steps given in this answer.