Most of the posts highlight what I am focused on and express work and personal experience. Reason I put them here - recall later or help someone else with similar challenge.
When having really slow digitalocean droplet (with 1Mb or even less capacity) you still can do your tests and, may be, put such instance in production (depends on what you have inside and network traffic). I like this guys as they offer SSD volumes and it is really fast. So there is no problem to extend your memory with swap.
Here is the way to set your swap to whatever number (change XXXX with your number, make sure you have enough free space).
Ok, let do this below:
sudo dd if=/dev/zero of=/var/swap.img bs=1024k count=4000 4000+0 records in 4000+0 records out 4194304000 bytes (4.2 GB) copied, 12.0326 s, 349 MB/s sudo mkswap /var/swap.img Setting up swapspace version 1, size = 4095996 KiB no label, UUID=b9da0933-f0d7-4379-8673-d527de03df22 sudo chmod 600 /var/swap.img sudo swapon /var/swap.img
Now, to check your if you set all correctly do the following:
free total used free shared buffers cached Mem: 506324 499648 6676 332 9220 414848 -/+ buffers/cache: 75580 430744 Swap: 4095996 0 4095996