Swapfile mount (/etc/fstab): "swap swap" or "none swap"

Question

There seems to be conflicting information on how to mount a swapfile.

swap swap:

none swap:

both:

Both ways work. What is the official recommendation and how does each way affect swapping?

Answer 1

In regard to the second field, for swap partitions, the Linux man page for fstab states:

For swap partitions, this field should be specified as `none'.

It has stated the same thing since at least 27 November 1993, the earliest man page I could find.

In practice it doesn't matter; if the filesystem type is swap, the system ignores the mountpoint field. I have one system where it is literally set to whatever and works fine.

UUID=b81f37e8-eddf-4969-9cea-8fdea73bd125 whatever        swap    defaults        0 0

But using the word "none" is intended to make it clear that the field is not relevant to the entry.