Who needs to reed this ?
The first version to appear after Netatalk 2.1 ie Netatalk 2.1.1, will support BerkeleyDB updates on the fly without manual intervention. In other words Netatalk 2.1 does contain code to prepare the BerkeleyDB database for upgrades and to upgrade it in case it has been prepared before. That means it can't upgrade a 2.0.x version because that one didn't prepare the database.
- locate the appropiate db_recover command that is part of the installed BerkeleyDB with which the old Netatalk version is linked with, eg run
# ldd PATH_TO_CNID_DBD_DAEMON | grep libd
- often the corresponding db_recover binary is name dbX.Y_recover where X.Y is the version of the libdb from above, it's probably installed in /usr/bin
- shut down the 2.0.x version of Netatalk
- using the found db_recover command run
db_recover -h PATH_TO_APPLE_DB_DIRECTORY
for all AFP volumes
- start the new Netatalk version