Source: https://askubuntu.com/a/1264577
In sleep mode, the content of ram is kept as it is, and the computer works on a very low power mode, so as to keep the ram content intact (as ram will lose the data if power supply is cut to it). But in hibernation, the ram content is stored in the swap space, so power can be completely cut off. Hence it is recommended to have swap size as large as the ram size.
- First disable the swap and delete it
sudo swapoff /swapfile
sudo rm /swapfile
- Create new swap space of size 16 GB (16 1024 = 16384).
bsis the block size. Basically bs count = bytes to be allocated (in this case 16 GB). Here bs = 1M (M stands for mega, so we are assigning 1MB block size) and we are allocating 16384 * 1MB (=16GB) to swap.
sudo dd if=/dev/zero of=/swapfile bs=1M count=16384
- Give it the read/write permission for root
sudo chmod 600 /swapfile
- Format it to swap
sudo mkswap /swapfile
- Turn on swap again
sudo swapon /swapfile
- Now reboot the PC for the above changes to take place.