Amanda 2.4.0 has introduced a major incompatibility in the Amanda protocol. This means that pre-2.4.0 clients won't interoperate with a 2.4.0 server, nor will 2.4.0 clients interoperate with pre-2.4.0 servers. You have to upgrade them all at the same time.

To ease the upgrade process Amanda has, from release 2.4.0 on, a configure flag (--with-testing) that will cause Amanda to use alternate service names (Amanda-test) instead of the standard ones. This allows you to keep using your old version of Amanda while you test the new one.

Depending upon the version of Amanda you are upgrading from, Amanda may use a different database library to store the backup information, and the new Amanda may not be able to read the old Amanda database files. In this case, you will want to do something like the following:

Before the upgrade (using the old version of amadmin):

	# cd /var/AMANDA/CONFIG
	# amadmin CONFIG export > zzz
	# mkdir backup
	# mv curinfo* backup
	

and after the upgrade (using the new version of amadmin):

	# cd /var/AMANDA/CONFIG
	# amadmin CONFIG import < zzz
	

and a month :-) after you are happy with the new version:

	# cd /var/AMANDA/CONFIG
	# rm -rf backup
	

After 2.4.0, the structure of the directory holding the index files was changed to have three levels instead of being flat. This greatly reduces the number of files in a given directory, which was a problem for some systems.

The new layout is:

where hostname and filesystem are "sanitized" versions of the names from disklist, i.e. '/' characters are converted to '_' and so on. This new naming convention matches the one used for the text formatted database.

A script is available to convert the flat directory structure to the new layout:

http://www.amanda.org/2.4-conv/msg00428.html