arver is a tool to manage encrypted harddisks. Imagine you are a collective with several admin members. Your servers have diffrent LUKS encrypted devices. Either you would need 1 password for every device which everyone needs to know or you use arver! Arver has 1 password for each device and for each member. This password is stored encrypted with the personal gpg-key in the data directory. The admins only need to know the password to the their own gpg secret key.
All you need to do is installing dropbear (a tiny SSH server) and BusyBox (a tiny shell, usually already installed) using apt-get. The initrd will be recreated automatically. Then reboot your computer.