我的加密的/ home如何工作,如何在另一个Linux发行版上通过cl使它工作?

I'm using an encrypted /home, but I have no idea how it works. I'm trying to install Arch Linux and use commandline tools like ecryptfs, but I can't figure out how to mount my ubuntu encrypted /home. Someone responded to my question on the Arch Forums and said that I needed my passphrase and salt, but I don't know what either of those is, or where to find them.