There's nothing wrong. In fresh installations of 17.04 we have a swap file instead of a swap partition, as mentioned in the release notes (if you upgrade rather than install afresh, you will still have a swap partition).
The swap file is located at
You can always check the status of swap with the command
Here's my output in 17.04:
$ swapon --show
NAME TYPE SIZE USED PRIO
/swapfile file 1.3G 62.2M -1
You can also see if it's being used with the
free command as usual
$ free -h
total used free shared buff/cache available
Mem: 1.9G 1.3G 152M 95M 423M 328M
Swap: 1.3G 62M 1.3G
See - working just fine.
According to the Arch wiki
There is no performance advantage to either a contiguous swap file or a partition, both are treated the same way.
It just provides a little more flexibility; it's easier to resize.
Minor note: Btrfs (alternative filesystem to ext4) does not support swap file usage, so you will need to create a swap partition yourself if you want to use Btrfs. But if you're brave enough to use Btrfs, you surely know what you're doing anyway ;)