Hi, as my problem is solved now - thanks to Nathan - I want to share my knowledge:
The problem was indeed changing device IDs of LVM2 volumes. One can see this by using the following command: stat --format="%D" <DIR on a LVM volume> Run this command after a reboot and it will show the device ID of the volume the directory resides (example: fb04). If this number changes, tar will see all files on this volume as new, thus an incremental backup is that large as an level 0 would be. Another method to see if the device number changes is to look at the (tar-)snapshot files on the client. On Ubuntu one can find them here: /var/lib/amanda/gnutar-lists/... There is a perl script, which parses these files and shows a summary how many times a specific device ID was found in the snapshotfile. The original script does not work with my perl version (5.10.1), but Nathan changed the script so that it worked for me. As I don't want to post the work of other people please ask Nathan to post his work. Solution: There is a Wiki article on zmanda.com with solutions: http://wiki.zmanda.com/index.php/Tar_dumps_every_file_in_a_level-1_backup_after_a_hardware_change For me, adding options to /etc/modprobe.conf didn't work (I guess because LVM is not a kernel module here). So I chose the solution from https://www.gnu.org/software/tar/manual/html_node/Incremental-Dumps.html#device-numbers to tell tar to do not check device IDs ( option --no-check-device). For that I added an application to amanda.conf and used this application in the dumptype for all DLEs residing on an LVM volume: define application-tool app_amgtar { plugin "amgtar" property "CHECK-DEVICE" "NO" } define dumptype nocomp-tar-nocheckdevid-medium { global program "APPLICATION" application "app_amgtar" [...] } More information for creating applications can be found here: http://wiki.zmanda.com/man/amanda-applications.7.html http://wiki.zmanda.com/man/amgtar.8.html Again, thank you Nathan for your great support and of course to all other guys, who tried to get me out of my troubles :-) /Thomas
