Q: Harddisk full with "other" and "backup" files

Hello everyone,

When I turn on my mac mini for 3 days my both harddisk are full. I can't restore from start up (Command +R), it said I don't have any backup. Some formus said my time machine do local backup and make use all my backup HD and my startup HD. My stratup HD fill with 995GB "other" file. HD2 fill with 1 TB of "backup". I only run mac OS X server on this machine, no other application! Who can help to clean up all the "other" and "backup" space.

OS version: 10.11.6

Machine: Mac mini Sever(Late 2012)