I want to decrease my startup process and I see the service named "screen-cleanup" What is that? Is it safe to remove?
First of all, the mystery application to which that particular startup service belongs, is screen, which you may have installed separately, or it may have come as part of byobu terminal multiplexer. Is it safe to disable? Basically, yes, but you won't be able to use screen. You can, however, still use byobu. I currently have it disabled, and writing this after a reboot.
Now, onto the investigation and some proofs. Every start-up process has a start-up scripts, and initialization scripts to those are located in
/etc/rc folders. There is several of them, depending on your system's run level. Run level topic is something separate from this question, but if anyone is interested, I recommend reading up on this answer from superuser.com, and man pages for
My current run-level is 2, and under
/etc/rc2.d/ I have the initializing script for screen-cleanup, S20screen-cleanup. If you cat it, you'll see that basically all it does is clean up saved sessions from screen (stored in /var/run/screen).
Disabling can be done through Start-up Applications (GUI) or by renaming the initialization script from S20screen-cleanup to K20screeen-cleanup ( more precisely , it is 'sudo mv S20screen-cleanup K20screen-cleanup' command).
What will happen if you disable this service ? Having rebooted my machine , I tried 3 things: enter screen, enter byobu, and
ls /var/run/screen . The result is that byobu still runs (probably because it falls back to using tmux,, which also comes with byobu), screen won't start (reports "Cannot make directory '/var/run/screen': Permission denied"
), and the said folder is not existent. But hey, the system is still running, everything still works, so you could say it's safe enough to disable that service, especially if you don't usually use screen or byobu.
P.S: Although this answer is somewhat late, I hope moderators will allow leaving it here, so it may be useful to other users who are looking into disabling some of the startup services.