Last night, my Ubuntu 19.04 suddenly became unresponsive, then on and off for a while. The fan started spinning rapidly, as a sign that much work was being done inside. I managed to start a system monitor, and the memory usage looked quite disturbing:
As you can see, my RAM filled up rapidly, invoking my swap partition, until both were full, at which point all memory seemed to be released, starting a new RAM-filling cycle.
I managed to reboot the machine, only to discover that the RAM eating started immediately again.
A top showed me that the offending process was tracker-extract, which I managed to uninstall, and after another reboot, no more RAM eating.
As it turned out, I had removed Nautilus in the process. sudo apt install nautilus installed tracker-extract again, but it has behaved itself since then.
Is this a known problem? Can I see somewhere what went wrong, so that I can prevent it from happening again?
I am also having this problem. When I extract a certain archive, tracker-extract will almost immediately fill up all RAM and swap. Upon reboot, it will do it again after a few seconds. Only solution is to boot in maintenance mode and delete the extracted folder. I don't know what file is causing it, so it's hard to file a bug report.
After hours of frustration I just force removed the tracker package.