Couln't hibernate

Question

I couldn't hibernate my system due to insufficient swap memory. Hence, I created a swap partition with the size twice of my RAM. However, when I tried to activate the partition and open fstab file, the file's content is as follows:

proc            /proc           proc    nodev,noexec,nosuid 0       0
/host/ubuntu/disks/root.disk /               ext4    loop,errors=remount-ro,user_xattr  0       1
/host/ubuntu/disks/swap.disk none            swap    loop,sw         0       0

What does it means? Is it an error? How can I specify my UUID?

Thank you