How to resize storage using LibreNMS Ubuntu image?

Hi guys,
I have been playing with LibreNMS since a few weeks, I used the Ubuntu OVA image to load it into my XenServer server. It worked great for weeks, but now it failed because of lack of partition space, unfortunately the OVA file created a 10GB virtual drive in XenServer, I resized the storage from 10GB to 500GB, but I’m not able to configure the Ubuntu server to resize the partition, do you know how can I do this?