Virtual Machines & Binary Compatibilty

[Richard L. Hamilton]

I don't know how it is now, but macOS/OS X clients on VirtualBox used to be a real pain to set up, starting with an ancient version of OS X and then updating to the desired level, with fingers crossed. Parallels (yearly subscription fee) is much better, but I know it does enforce the Server requirement (see next paragraph).

Also, for Snow Leopard, the OS license requires that OS and client both be OS X Server, and virtualization software will probably enforce that regarding the client (although by creating the right file in the image, it might be possible to fake having Server).  Good luck getting media for that.

Additionally, where non-identical CPUs are involved, I think some ports need to be built locally, because of the optimizations they do.  I think ffmpeg may be one, and one or more math libraries also; but I don't know of any authoritative list of those.  I think one might suppose that ports for which no prebuilt binaries exist (even for newer OS versions) might be among those, but I don't know of any straightforward way to construct an authoritative list of such packages, either.

There are a few files outside of /opt/local (or whatever installation directory), such as those in /Applications/MacPorts, and probably some in /Library/LaunchDaemons and/or /Library/LaunchAgents; maybe
a few others too.  One could in principle find them all by running port contents installed  and inspecting the output.

But even then copying installations from one machine to the other, unless they were the same year and model and CPU and of course OS version, would IMO be a really bad idea.

I haven't done it, but there are in general ways to build and package port binaries, which can then be made available to other machines.  There's probably documentation available for how to do that. Again, there will be ports for which that's not a good idea either. So expect to have to learn some things, dig around, ask more questions  etc, if you want to do it right. :-)  I don't have the answers, not having been involved in the creation of any of this, nor having had the need to pursue such things for myself, as yet.

> On Aug 31, 2019, at 15:13, Bjarne D Mathiesen <macintosh at mathiesen.info> wrote:
> 
> Q : Will this scenario work ?!?
> 
> If i create a VM of 10.6.8 in VirtualBox on my 2012 MacPro w/ Xeon CPUs,
> can I then rsync my macports installation to a Core 2 Duo based Mac Mini
> without any problems ?!?
> 
> -- 
> Bjarne D Mathiesen
> Korsør ; Danmark ; Europa
> ----------------------------------------------------------------------
> denne besked er skrevet i et (næsten) M$-frit miljø
> MacOS X 10.13.6 High Sierra :
>   17" 2011 MacBook Pro ; 2.8GHz Intel Core i7 ; 16GB 1067MHz DDR3
>   2012 Mac Pro ; 2 x 3.46GHz 6-Core Xeon ; 48GB
> MacOS X 10.6.8 Snow Leopard :
>   Mac Mini ; 2GHz Core 2 Duo (64 bit) ; 4GB (3GB actual) 667MHz
>   Mac Mini ; 1.83GHz Core Duo (32 bit) ; 2GB 667Mhz
>