Can you put user temp files in /tmp?

Question

Can you put files in /tmp? A friend of mine was telling me never to do that, it could bring down a machine. Is this true?

Answer 1

It's what it's there for. The only potential problem is if you run out of space. You should be aware that the contents are generally not preserved across reboots.

Answer 2

Depends. If it's actually a temporary file that's fine.

There are two situations where it might bring a machine down (or at least impair operation):

1. There's no limit on it and you fill the root disk. This is even more of a problem if /var is the same slice/partition.

2. It's RAM and there's no limit so you use up all of the RAM on the machine.

But in general, the point is as a place for users to store temporary files (i.e. ones that may be deleted by the administrator or will disappear if the machine reboots).

Answer 3

If you're writing software for a multi-user system, make sure you create temp files securely. If writing shell scripts, the mktemp utility does this easily.