Space Usage In root has Exceeded 95% threshold

Hi

We have a DD9500 device with 5.7 os, and we see a critical alarm about the size of root , please help me to solve this issue...

problem:   /     size is 1.8gb consumed of 2gb.

we are going to upgrade DDOS to 6.2, but now it is operetional and we cannot upgrade and reboot DataDomain now.