Generate fstab in Arch Linux

fstab-generate-arch

First, install arch-install-scripts:

sudo pacman -S --needed arch-install-scripts

Secondly, mount your partitions in all the internal hard drives.

Thirdly, generate and validate your config by piping it out to stdout:

genfstab -U -p /  | less

If all looks green, proceed to overwrite your current fstab with the new entries:

#genfstab -U -p /  > /etc/fstab

Run that command as ROOT. 

Tip: It may be wise to add the nofail option for some partitions, namely NFS and the likes, so your system can boot even if shit hits the fan.