Recently, I ran into the following error while installing some software on Ubuntu 14.04:

virtual memory exhausted: Cannot allocate memory

Not good - but the fix is easy – add some swap space to your instance. The following is a list of commands you can use to successfully resolve this problem:

85  cd /
87  sudo dd if=/dev/zero of=swapfile bs=1M count=3000
88  sudo mkswap swapfile
89  sudo vi /etc/fstab

Now add the following like to /etc/fstab:

/swapfile none swap sw 0 0

And do not forgot to reboot …..

   95  sudo reboot

How lets make sure the swap space exists:

ubuntu@ip-172-30-0-233:~$ cat /proc/meminfo | grep '[Ss]wap'
SwapCached:         3720 kB
SwapTotal:       3071996 kB
SwapFree:        3059708 kB

As you can see, you now have 3GB of swap space on your device !!! Not - EC2 comes with ZERO swap space by default - so it might be no a surprise if you are seeing this issue - especially on a t2.micro instance.