Agaric

Part I: Private and Public Keys

SSH public key authentication requires the user to create a public/private key pair on her machine. It's easy:

ssh-keygen

A key pair will be generated (it is ok to hit enter every time you are prompted by the key generator) and stored in ~/.ssh. The default names are id_rsa/id_rsa.pub and id_dsa/id_dsa.pub depending on the encryption algorithm. For each device used to connect to remote machines via ssh this must be repeated. It's not a good idea to spread the private key.

Create a custom module that will display special upgrade instructions right on the Update Status report page. This custom module can have a directory of includes for each module with custom instructions.

Some modules have libraries (RDF, WYSIWYG) that would be wiped during a typical upgrade. Some projects require patching a module. Sometimes a module is purposely left not-upgraded because the upgrade causes bugs (either due to dependency on custom code, or because the upgrade path is broken).