We're working on a project in which the customer needs the Ubuntu server on which a web app and database are running to be "encrypted at rest". What's the best way to implement this?
Sorry but I cant understand what you mean with "encrypted at rest"
if you want to encrypt parts of the system i would recomend lukscrypt and lvm.
you will need to have installed LVM when you install the server I would just but the database and the files which you need to keep encrypted on a logical volume in LVM and require manual opening the encrypted partition after each reboot