External disk as system volume on different macs password issue I have few macs (office, home, macbook) and decided to use external disk as system boot volume (thunderbolt) for convenience purposes (web development, macports, etc, very hard to maintain same versions/databases across different computers).

It works well, BUT.. each time I login on different computer - Macos ask me to re-authentificate iMessage/iTime, then when I try to use any software bought from Appstore, it asks for password, very annoying.

I thought about changing serials to make it same across different computers, but not sure its good practice, maybe it could be done by changing UUID or so on.

Anybody have experience with situation like that?
I believe the files in ~/Library/Preferences/ByHost are computer-specific. For instance, iTunes stores the volume of each computer there. 
Hope this helps!