mount --bind <em>source</em> <em>target</em> command links one folder to another. For example I put an extra drive in a Linux box that I want to store a specific folder on. I may store some other folders on it, and I really don’t want to have to partition it ahead of time. Basically I just want an easy way to move folders to it as needed.
However, the mount command doesn’t persist across reboots. So instead I add lines like the following to /etc/fstab:
/mnt/drive2/firewall-log /var/log/firewall-log auto bind 0 0
To get the new mount to work immediately simply type:
sudo mount -a
This is also a handy way to create shared folders among multiple users.
If I were really cool, I’d learn how to use LVM, but binding directories is just so quick and easy.