Went through the tmp dir of a server, found odd stuff

mariond

I'm a Rails programmer and support a number of Rails projects. Since we lost our Sysadmin some time ago, I'm learning how to replace him.
For the chapter on the directory tree I logged onto our server and looked through the directories. It's interesting to see what's in a live server's directories... especially since on my Mac a lot of the directories the course mentions don't exist.

In /tmp I found a lot of "files" like the course said, but I also found (a) some shell scripts and (b) a ton of passenger-error-.....html files.
I googled those and found that the passenger-error-files are dumped there by Passenger when it can't start.

Now naturally I'd like to ask: Generally speaking, how safe is it to delete files in there? (It goes without saying that I should absolutely know what the file is for.) I probably need to be root. I really want to keep my hands off system-operated directories, but it seems there are files that never get cleaned up. Does the system ever do any cleanup at all?

coop

/tmp is ... temporary. > Does the system ever do any cleanup at all?

Policy depends on distribution. On Ubuntu /tmp is cleared every time there is a reboot. On Fedora (by default) /tmp is purely a ram disk which means it also clears on reboot. On RHEL/CentOS system a utility called "tmpwatch" clears out all files that are not used for 10 days and is run every day. Other systems may treat it as any other directory and leave it up to you to clean up periodically.

So to repeat /tmp (and /var/tmp) contain files that can safely be discarded, but you may want to look at to see what has recently transpired on your system. Generally large files are not good to put there

mariond

OK thanks... my system is a server, so it's hardly ever rebooted... at least, some of those files are well over a month old. I'll limit myself to watching the situation for now