Aufs to overlayfs2 migration, volumes

I’m running docker 1.12.6 aufs storage driver + volumes in production on ubuntu 16.04 LTS with minimal side-effects and considering upgrade to 17.x and overlayfs2 storage driver.

From what I’ve read in the manual it’s not clear, is the only thing I need is to change storage driver in daemon config during upgrade, in a relation to the user data stored in volumes. Or there some export/import procedure needed during storage driver upgrade.

Thank you for the answers.