I've got a Linux-based OS installed on a partition I want to shrink. Want to avoid reinstallation or losing/corrupting data, if possible.
D O A BACKUP of sensitive data. At the very least on the partition, you want to shrink. Neither I nor geparted can be held responsible if you screw up.
Now to the procedure:
The picture is a little messy but don't get scared (
Here is a text version of the steps numbered as in the picture:
This will not work with all partitions. It can be more complicated for Mac partitions or logical volumes.