By default, disk drives do not automount in Ubuntu Server Edition. If you are looking for a lightweight solution that does not depend on HAL/DBUS, usbmount is a good choice.
The USBmount Debian package automatically mounts USB mass storage devices (typically USB pens) when they are plugged in, and unmounts them when they are removed. The mountpoints (/media/usb[0-7] by default), filesystem types to consider, and mount options are configurable. When multiple devices are plugged in, the first available mountpoint is automatically selected. If the device provides a model name, a symlink /var/run/usbmount/MODELNAME pointing to the mountpoint is automatically created.
The script that does the (un)mounting is called by the udev daemon. Therefore, USBmount requires a 2.6 (or newer) kernel.
USBmount is intended as a lightweight solution which is independent of a desktop environment. Users which would like an icon to appear when an USB device is plugged in should use the pmount and hal packages instead.
USBmount is licensed under an ‘all-permissive license’ (i.e. everything is allowed, as long as the copyright and license notices and the warranty disclaimer are preserved). See the debian/copyright file in the package for details. (USBmount website)
Install usbmount in Ubuntu:
usbmount is available in Ubuntu repository, use this command to install it:
sudo apt-get install usbmount