A little note before we begin, the machine was constantly active for 5 to 7 days straight, the only reason it was shut off at some point was to turn it back on immediately due to locking or unusable behavior (Not a complete freeze, as the cursor was still moveable, these happened after doing stuff like running a certain game (GTA IV) or running the command "compiz --replace).
I have a Ubuntu 14.04 machine, and something has gone fishy with it. First, Skype had a disk i/o error, I moved 40 GB of space to an external drive and rebooted to make it work fine, then today it happens again, I notice that in my home folder it reads that there are 0 bytes worth of free space, so I hit Ctrl+H to view hidden files and folders, and notice that my Cache took up a whopping 746 GB of disk space, I went in the folder and checked everything there too, the folder lxsession had around 740 GB, I opened that up to see a single folder called "Lubuntu" (Ubuntu was installed, but I also installed the "lubuntu-desktop" package), in that was a run.log with the same space, I deleted that and emptied the trash, and 5 minutes later I'm down to 10kb disk space? I rechecked, the file was gone, I freed up more disk space only for it to become used again, what should I do?
Note: I have not experienced any "Out of the blue" crashes, even after rebooting the problem persists, Also, I moved folders from "/home/me" to my external drive, and since that drive is mounted in "/exhd", I bind mounted the folders I moved as if they were still on my hard disk, the external drive seems to have no problem and uses the NTFS file system, while my internal drive has my install partition as the problem and uses the EXT4 partition.