Restore from backup

[Ryan Schmidt]

On May 16, 2012, at 00:28, Adam Dershowitz wrote:

> I have macports, with many ports installed.  
> I had my harddrive fail, but have a recent timemachine backup.
> But, when I tried to restore, after a fresh OS install, at first when I clicked transfer, nothing would happen.  I finally opened the users that timemachine had selected to restore.  Several of these users were listed as "this user data doesn't need to be transferred". When I unselected those it was then willing to do my restore.  (I was very nervous for a while!) 
> Those users,also showed as 0kb of data.   The names were: avahi,macports, messagebus, and polkituser.   I believe that these were all user accounts created by macports.  I think that since they are just names, with no data, that is what "confused" timemachine restore.   But timemachine should still restore all of macports.
> My question is what I need to do to get the ports to again function.  I assume that macports will not work once my restore is done (still a few hours) since those user accounts will be missing.  
> I know that I could blow away my whole install of macports,but then I will have to rebuild all my ports, which will take a long time, and defeat the purpose of having a backup.
> So, is it possible to just create those users?  If so, what should I do to get them created?

The user accounts were created by the various ports for a reason, which usually includes that those ports will install files and/or directories owned by that user account. If the user account is not there when the files are restored to your drive, then the files will by owned by I have no idea who. So the safest thing to do might be to rebuild those ports that create user accounts. That will recreate the accounts and get the file ownership set correctly. From the ones you mention:

macports: created by the MacPorts install program; re-download the MacPorts 2.1.0 installer and run it; it'll create the user for you and won't disturb your installed ports.

avahi: created by the avahi port; rebuild it (sudo port -n upgrade --force avahi)

messagebus: created by the dbus port

polkituser: created by the policykit port