Export your block devices with AoE
Imagine you have a machine with all of his disk full and another with unused Gigabits, and you don't want to move the data from one to other. Why not using the second's disk on the first, you can do it with iSCSI but you can do it with ATA over Ethernet (AoE) too. It's the second method I'll explain is this article.
All of this was made with two computer running Debian Etch.
Prepare the kernel
First check if your running kernel have AoE, the config option name is CONFIG_AT_OVER_ETH, have a look at fig1, my kernel has AoE in module
host:/# grep ATA_OVER /boot/config-`uname -r`
If not, configure your kernel and activate AoE in core or in module like you prefer