The swap partition is not installed during Ubuntu installation. Create a new swap partition without reinstalling the system.

1. Download the gparted partition tool, compress or expand memory, and create a new swap partition.

& sudo apt-get install gparted

2. Activate swap partition

& mkswap /dev/sda5 
Setting up swapspace version 1, size = 2097148 KiB
no label, UUID=cc64ac36-f5b0-4877-afe6-a49e76c72336

& swapon /dev/sda5

3. Modify the fstab file

& sudo gedit /etc/fstab

4. Check the swap partition activation status

& free -h

Activation successful!