Add swap space to Ubuntu
Truffle compilation was crashing with memory-overrun issues in my 512 MB basic droplet. So I added 2 GB of swap space with following commands.
Make sure you have no swap config previously. There should be no output.
$ sudo swapon --show
$
The simple way of doing this is by creating a swap file. Lets look at all the partitions to see how much free space in each of them.
$ df -h
kaba@ubuntu-512mb-blr1-01:~$ df -h
Filesystem Size Used Avail Use% Mounted on
udev 238M 0 238M 0% /dev
tmpfs 49M 5.9M 43M 13% /run
/dev/vda1 20G 5.2G 15G 27% /
tmpfs 245M 24M 221M 10% /dev/shm
tmpfs 5.0M 0 5.0M 0% /run/lock
tmpfs 245M 0 245M 0% /sys/fs/cgroup
/dev/vda15 105M 3.4M 102M 4% /boot/efi
tmpfs 49M 0 49M 0% /run/user/0
tmpfs 49M 8.0K 49M 1% /run/user/1000
$
/dev/ are virtual filesystem and are not usable.
* I'm gonna create my swap file in /dev/vda1.
Use fallocate utility to create a preallocated file in root directory.
$ sudo fallocate -l 2G /swapfile
dev/vda1 is mounted on /
* 2G specifies 2 GB of space. Use whatever size you want in that place.
Make the is file accessible to root user alone
sudo chmod 600 /swapfile
Mark the file as swap space
$ sudo mkswap /swapfile
Enable the swap file, so your system will start using it
$ sudo swapon /swapfile
Done!
Now swapon command shouldn't return an empty result
$ sudo swapon --show
NAME TYPE SIZE USED PRIO
/swapfile file 2G 771.6M -1
Make swap settings permanent
You need to edit /etc/fstab file. So better take a backup of it.
$ sudo mv /etc/fstab /etc/fstab.orig
Update the file with swap information
$ echo '/swapfile none swap sw 0 0' | sudo tee -a /etc/fstab