is it save to upgrade from Ubuntu 11.04 Natty to Ubuntu 12.04.1 LTS without losing all mining configurations?
(or what configurations are to save or to make new?)
TIA
Ubuntu upgrades for me have been about 50/50: Half the time the upgrade is successful, half the time it fails catastrophically.
The Ubuntu upgrade application doesn't back anything up, so if it fails at any point your system is essentially ruined.
Back up back up back up.
Even if the upgrade succeeds I've found that I end up with some kind of broken frankenstein OS that is half the old version, half the new version.
Instead of upgrading I recommend you back up your data, wipe and install the new version, then restore your data.