Getting the Size Right
I've heard and read many arguments over the years about the correct amount of swap space on Linux. The requirement and reality has changed a lot for swap over time and this article is the best I've read summarising it all in a convincing manner.
The short conclusion from this article is:
swap = 2GB;
if (ram <= 1GB) {
swap = ram;
}
else if (ram < 4GB) {
swap = ram / 2;
}
Adding a Swap File
I love the simplicity with which you can add and remove swap files in
runtime. This is how I added a 1GB swap file, adding an entry for it
to/etc/fstab and activating it:
# dd if=/dev/zero of=/var/lib/swap.file bs=1024 count=1024000
# mkswap /var/lib/swap.file
# echo "/var/lib/swap.file swap swap defaults 0 0" >> /etc/fstab
# chmod 0600 /var/lib/swap.file
# swapon -a
That's it. Runningfree -m shows that I now have 1GB swap
available. There's no greatness where there's no simplicity. And Linux
is full of such simplicity :-)
