How to Manage File Permissions in Detail (ACL)

There's a hidden, commonly unused feature of linux that I find very useful. The feature is Access Control Lists, or ACL for the file systems, and allows to manage file permissions easier and in more detail than the default User-Group-World system. Enabling this feature you can control permissions on a per-user basis, very much like Windows.

Step 1 The first thing you need to do is to mount (or remount) the chosen partitions with ACL enabled. You can use fwfstab (image) or edit the /etc/fstab file. You need to have "rw,acl" in the options column in that file instead of "defaults", for example:
/dev/sdb5 /mnt/datos ext3 rw,acl 1 2

Step 2 If the partition is already mounted, you'll need to run as root "mount -o remount /mnt/datos", and if not, you just run as root "mount /mnt/datos".

Step 3 With Eiciel installed, you can select any folder in the partition you've just mounted, right-click-> Properties, and you will have a new tab called "Access Control List" that allows you to manage in great detail users permissions. You can, for example allow a single user read access to your home directory, and write access to a certain folder in it and set the default permissions for new files and folders.