Ah, I now see what you mean. With the exceptions of /var/lib/dbus/machine-id and /var/run, which need to be shared for certain bits of software to communicate properly, /var is currently isolated by default. If a website is hosted at /var/www or e-mail contents stored at /var/spool/mail, a naive implementation of the rollback system swsieber described would roll back the website and e-mail as well. Bedrock can be easily configured to make such directories shared across the system and exempted from such a rollback system; hopefully any user who attempts such a workflow would catch this issue and change Bedrock configuration accordingly. I should probably investigate making such configuration default.