[sgs1370]

thanks - this is a good heads up. I asked my team to back up anything not checked into our git repo to some disk not controlled by OSX, and btw don't rely on your time machine, who knows if some bug in the new FS might affect that also. Better safe than sorry. I finished my note with a suggestion to just wait a few months before upgrading to 10.13

[tinus_hn]

You can also keep your Time Machine disk disconnected during the upgrade so it won’t be touched by the installer. In my opinion not a bad idea anyway.