Leopard sandbox on a Tiger Powerbook

[AlexFriedman]

I'd like to try Leopard but don't want to risk the day-to-day usability of my Powerbook. I want to do some thorough testing before a full cut-over, because I am concerned that after the update some key capability may not work; I have installed a number of binaries on the "Unix" side, for example.

My thought was that the "sandbox" offered by SD almost does what I want. However, because in my sandbox my whole user folder is just an alias / soft link, I can't have a separate personal Library folder. I fear that personal Library folders may not be backward compatible, so that by updating my sandbox to Leopard I will break the Tiger partition.

What I'd like is a variant sandbox that creates a new user folder on the Leopard partition, with its own Library folder, but with aliases / soft links to all the other contents of my user folder.

Is this possible? Or perhaps am I missing something, and what I suggest is not advisable or necessary? Any comments would be appreciated.

[dnanian]

You can't sandbox Leopard from Tiger, Alex: it's definitely not going to work. Too many changes all over the system in the new OS.

[AlexFriedman]

You can't sandbox Leopard from Tiger, Alex: it's definitely not going to work. Too many changes all over the system in the new OS.

Thanks for the reply. However ...

What I really want is a separate partition with Leopard installed on it --- and a home folder with its own library and everything else a soft link to the corresponding item in my home folder on the Tiger partition; likewise for the non-Apple apps. I don't see why that should not be possible.

Could I achieve it by doing a complete SD backup of everything to the second partition, excluding all of the items in my home folder except Library, and all the non-Apple apps? Then I'd update the second partition to Leopard, in place, and finally make a bunch of aliases by hand. That'd be labor intensive, but might be automated.

Would it work? Or if not, what _should_ I do?

[dnanian]

You can't do it, Alex. While it'll "technically" work, the file system in Leopard has more security elements that will mess with your Tiger install, and preferences (etc) are not backward compatible. Don't do this.

[AlexFriedman]

You can't do it, Alex. While it'll "technically" work, the file system in Leopard has more security elements that will mess with your Tiger install, and preferences (etc) are not backward compatible. Don't do this.

Beating a dead horse, maybe, but ...

I believe I could have two separate full systems on one physical disk by having two partitions -- SD all of partition 1 to partition 2, then update-install Leopard on partition 2 -- is that right?

Could I then erase most of my home folder on partition 2 and insert aliases to the corresponding items on partition 1? That ought to be like accessing another disk that just happens to have Tiger on it but is not the boot disk. Is that right?

As for applications, there would be two sets of preferences for each app, one on each partition, and tuned for its own OS.

My goal is to have Leopard and Tiger coexist for a couple of months on one Powerbook w/o duplicate copies of all user data and apps -- is there any way to do that?

[dnanian]

No. Do not alias your home folder between Tiger and Leopard. You're asking for pain. Don't do it.

[AlexFriedman]

No. Do not alias your home folder between Tiger and Leopard. You're asking for pain. Don't do it.

OK -- thanks for the warning -- but actually I was never suggesting doing that -- I would just alias individual items within the home folder, such as documents, photos, etc. That way all the system-specific data in <user>/Library would be unique to each partition.

[dnanian]

I think it's a mistake. Of course, you can do what you want... but I would not try to share between Tiger and Leopard.