Will Lion restrict boot devices?

[zephonic]

I read on another forum that Lion machines will ONLY boot in Lion and cannot boot up in SL or older versions of OSX.

That would be a dealbreaker for me. Is that true? Why would they impose this sort of restrictions?

I was thinking with Lion I'd keep a clone of my current system (SL) on an external drive just in case I need something that uses Rosetta or whatever.

On a Lion machine, would I no longer be able to boot from an external (bootable) drive with my old SL system on it?

It sounds so unlikely...

 

[simsaladimbamba]

That restriction is already present in current or older Mac OS X versions.
If you bought a Mac with 10.6.7 on it, you can't install 10.6.6 or lower on it or boot from an external HDD with 10.6.6 or lower on it.
The same will be the case with 10.7. If your machine came with 10.7.1 for example, you can't boot from an external HDD with 10.7 or lower on it.

 

[zephonic]

OK, but why is that?

My '07 Mac is not restricted that way.

 

[simsaladimbamba]

OK, but why is that?

My '07 Mac is not restricted that way.

You 2007 iMac probably came with Mac OS X 10.4 or 10.5, but you can't boot Mac OS X 10.3 or versions of 10.4, that haven been available before the release of your iMac on it, can you?

It has something to do with drivers, as newer Macs come with newer hardware that have with newer drivers, which are not included in OS X versions, that have been out before the Mac with the new hardware was even released.

For instance, the new 2011 MBPs came with a special build of 10.6.6, and one can't (without hacks) install any normal 10.6.6 or lower version on those Macs.

Is that understandable?

 

[zephonic]

Yeah, it came with Tiger and I guess I never tried to revert to Panther. 😀

But even after updating to SL I could always go back to older versions on external devices.

So that means I'll have to keep this machine around to run legacy stuff then.

 

[simsaladimbamba]

Yeah, it came with Tiger and I guess I never tried to revert to Panther. 😀

Panther was a bad example, as it isn't even Universal and would include code for x86 hardware.

But even after updating to SL I could always go back to older versions on external devices.

And that will be the same once you install Lion on this exact machine.
My 2007 iMac came with Tiger and ran Leopard, now runs Snow Leopard and even ran Lion for a while. And I could revert back to Tiger if I wanted.
The same goes for my 2009 MBP, which ran Leopard, now runs Snow Leopard and even ran the dreadful Lion once.

 

[Icy1007]

Panther was a bad example, as it isn't even Universal and would include code for x86 hardware.


And that will be the same once you install Lion on this exact machine.
My 2007 iMac came with Tiger and ran Leopard, now runs Snow Leopard and even ran Lion for a while. And I could revert back to Tiger if I wanted.
The same goes for my 2009 MBP, which ran Leopard, now runs Snow Leopard and even ran the dreadful Lion once.

QFT, Lion is amazing.

 

[simsaladimbamba]

QFT, Lion is amazing.

In your eyes it may be, in mine it isn't.
But there are countless thread discussing the other sides of Lion.