If it were me I would take the easy option and mount the second partition as /home.
Currently you do not have a separate /home partition. A separate partition is handy if you decide to reinstall Linux.
Mandriva Control Centre can do all the heavy lifting for you.
First you have to log on as root user because you cannot reassign your /home while logged on as a regular user. Mandriva makes logging on as root hard work. A simple way of doing it is Ctl+Alt+F1 to get a console, log in as root user, then
service dm stop
You will then have a red desktop running as root.
Now in Mandriva ControlCentre>LocalDiscs>ManagePartitions>ToggleToExpert
Select the partition and format it as ext3/4 or whatever you want, then select the mount point to be /home
A pop up will appear saying that the /home folder is not empty and would you like to transfer the files to the new partition. Say 'Yes', and the job is done.
The space vacated on the original Linux partition can now be used for more programme files.
Log out and at the text prompt enter
service dm start
and you will back in your graphical environment with your new partition in use.
Easy... But as always backup all critical data before taking advice from strangers on the internet.