On creating Mac OS X backups for SL DVDs

[pepin-et-rumeur]

Hi, I've done a couple of backup DVDs for relatives who had misplaced their own, but some of them complained that either the DVD would be ejected or it couldn't be booted from, or it would ask to restart but there would be the question mark screen, or again that the reader would make loud noise and the fan would be at top speed.

So I'm wondering what determines if a DVD is bootable or not (C key), why would a DVD show up or not when holding alt key and if some older Macs can't read single layer DVDs.

 

[ezramoore]

Sounds like you're trying to diagnose multiple problems.

If you make an image of a bootable disc, when you burn that image to a new disc it will remain bootable.

 

[simsaladimbamba]

If those discs are not copy protected:

How To Make Copies of DVDs

 

[pepin-et-rumeur]

If you make an image of a bootable disc, when you burn that image to a new disc it will remain bootable.

It's what I do so i'ts also what I thought should be the case.
I used retail disks of Snow Leopard and Leopard, for some people it worked for some it didn't.

How To Make Copies of DVDs

That's unrelated

 

[ezramoore]

Again, sounds like you have a multi-variable situation here. I'd be willing to bet that your discs were all fine.

Apple using slot loading ODDs which are known to fail early and in some interesting ways.

 

[Nermal]

That's unrelated

No it isn't. Those steps should work, whether it's a bootable OS X DVD or an unprotected movie.

if some older Macs can't read single layer DVDs.

They should all read single layer DVD-R, but I'm aware of at least one model that requires "dark" DVDs with a blue or green surface and won't read the cheaper ones with a pale surface.

 

[pepin-et-rumeur]

Again, sounds like you have a multi-variable situation here. I'd be willing to bet that your discs were all fine.

Apple using slot loading ODDs which are known to fail early and in some interesting ways.

Can you elaborate on that ?
Does it mean that the same should happen with a pressed DVD ?
Would a hard drive or USB key copy work better ?

 

[ezramoore]

Does it mean that the same should happen with a pressed DVD ?

Yes, I think that it is pretty likely that at least some of them have failing ODDs.

Would a hard drive or USB key copy work better ?

Probably, they are also incredibly easy to make.

 

[seveej]

Hi, I've done a couple of backup DVDs for relatives who had misplaced their own, but some of them complained that either the DVD would be ejected or it couldn't be booted from, or it would ask to restart but there would be the question mark screen, or again that the reader would make loud noise and the fan would be at top speed.

So I'm wondering what determines if a DVD is bootable or not (C key), why would a DVD show up or not when holding alt key and if some older Macs can't read single layer DVDs.

Lemme get this straight, you've made backup copies for relatives by making copies of you snow leopard installer disks?
Besides the points mentioned earlier two question come up*:
- are the macs in question (which have trouble) intel macs?
- are the copies made of your grey disk (which is hardware specific) or from the multicolored retail disk?

* sorry if these questions are dumb, but based on what you've written, I could not exclude them.

And yes, some really old macs cannot read dvd's, but more troublesome is that many old "combo" drives fail and stop being able to read dvd's (but continue to read cd's). Also, at least leopard (retail) was a double layer DVD.

RGDS,

 

[Bear]

...
So I'm wondering what determines if a DVD is bootable or not (C key), why would a DVD show up or not when holding alt key and if some older Macs can't read single layer DVDs.

All Macs that can read DVDs can read single layer discs.

As for the boot-ability issue... Is the machine newer than the OS they tried booting from? This could cause all sorts of issues. Or is it too old to be running that version of OS X?

Of course is their DVD drive working properly is a good question for an older system as well.

 

[pepin-et-rumeur]

Lemme get this straight, you've made backup copies for relatives by making copies of you snow leopard installer disks?
Besides the points mentioned earlier two question come up*:
- are the macs in question (which have trouble) intel macs?
- are the copies made of your grey disk (which is hardware specific) or from the multicolored retail disk?

* sorry if these questions are dumb, but based on what you've written, I could not exclude them.

And yes, some really old macs cannot read dvd's, but more troublesome is that many old "combo" drives fail and stop being able to read dvd's (but continue to read cd's). Also, at least leopard (retail) was a double layer DVD.

RGDS,

I use retail (not the model specific) disks of 10.5.6 UB and 10.6.0 Intel
The Macs are Intel for Snow Leopard and mostly PPC for Leopard
They came with those systems so they are not too old or too recent.
(I once tried the backup DVD on my too recent Mac and I was able to boot from it but got a kernel panic instead of the install screen...)

I feel like they are not working because they are burned and not pressed, even if the system info says they can read DVD-R. Some people tell me that other DVDs are read fine...


How can I determine if it's their DVD reader that is malfunctioning or the model that is not compatible (for what reason i wonder) or something else ?

 

[pepin-et-rumeur]

Nobody knows ?