Swap turned off after reboot, but it works after turning on swap with this command
sudo swapon /media/oleg/5C2C1D0A2C1CE0B6/swapfile
I have Ubuntu 18.04 installed on SSD. I have HDD with NTFS file system. I created swap file on NTFS partition not to put it on SSD.
/etc/fstab looks like:
UUID=26a50687-bfb3-4486-b822-9884130669de / ext4 errors=remount-ro 0 1 # /boot/efi was on /dev/sda1 during installation UUID=E055-53B9 /boot/efi vfat umask=0077 0 1 /media/oleg/5C2C1D0A2C1CE0B6/swapfile none swap sw 0 0
The computer has 8Gb, now it works ok without swap, but maybe it makes sense to add swap file just in case.