How to create new partition from existing Linux partition having data?

Use either Gparted or else go to the disk utility U'll be provided with enough info to make necessary partitions. But if U have left the installation to use the entire partitioning by itself i.e.  use entire disk U might have a little trouble. Then using Gparted will not be helpful to U.

you can also use GParted application.

Very good question. We can create partition from lvm based volume groups. First, shrink existing volume and create partition from free space.

 

This is not possible from jourling file system like ext3, ext4 direct partitions.

if you are using LVM you can reduce the size of one partition and use this space to create another one or extend it .
look for the following commands : vgdisplay lvdisplay lvreduce lvextend lvcreate

its very easy2 create partition..................just read the instructions onlyyyyyy...........