How to boot rMBP from external disc?

[aware]

Anyone?

 

[simsaladimbamba]

When the bootable disc is connected to your MacBook Pro with Retina Display via USB or Thunderbolkt, hold down the OPTION/Alt key right after the startup chime and select the item you want to boot from.

Mac OS X keyboard shortcuts

To learn more about Mac OS X: Helpful Information for Any Mac User by GGJstudios​

 

[aware]

Hi, i tried but rMBP only shows the option of boot from hd and boot from recovery. It does not show the external drive?

 

[simsaladimbamba]

Hi, i tried your method but rMBP only shows the option of boot from hd and boot from recovery. It does not show the external drive?

What is on the disc in the external drive then?

 

[aware]

DMG image. It is a diagnostic tool.

 

[simsaladimbamba]

DMG image. It is a diagnostic tool.

How did you burn the DMG? DMG files are not bootable, thus just burning the DMG as a file to a CD or DVD will not work getting a bootable disc.

Steps 7 and following should help you getting a bootable DVD: How To Make Copies of DVDs

 

[aware]

Hi, there are some steps i don't understand. Step 3 ask us to create new image from disc, the pic shown is for dvd but mine is downloaded dmg file. Should i create a new image from dmg? If i create a new image, what format and partitions should i choose?

 

[simsaladimbamba]

Hi, there are some steps i don't understand. Step 3 ask us to create new image from disc, the pic shown is for dvd but mine is downloaded dmg file. Should i create a new image from dmg? If i create a new image, what format and partitions should i choose?

That is why I mentioned, that step 7 and following are the steps helping in your case. Maybe I should have clarified, that steps 1 to 6 can be ignored.

 

[aware]

That is why I mentioned, that step 7 and following are the steps helping in your case. Maybe I should have clarified, that steps 1 to 6 can be ignored.

Step 7 ask us to select a DVD disk image (.cdr) from column list on the left of the Disk Utility window, but mine is a dmg image. So i just burn dmg or do i need to convert to cdr?

 

[simsaladimbamba]

Step 7 ask us to select a DVD disk image (.cdr) from column list on the left of the Disk Utility window, but mine is a dmg image. So i just burn dmg or do i need to convert to cdr?

Further into that sentence it also teils you can Open an external image, it does not need to be a DMG.

 

[aware]

Further into that sentence it also teils you can Open an external image, it does not need to be a DMG.

Sorry but i don't understand, what external image? I only got dmg file.

 

[Jedi]

Hi ,

I too have a question , maybe someone would help. :

So when you extract the “InstallESD.dmg” , then copy > then paste to "Source"
to make it bootable ( USB Flash Drive ).

Now is where I get confused , I have not done any of this yet , but buying any Mac and not "optimizing" it seems like a waste __ IMO.

So , now I have my USB F/D at the ready and my computer is OFF ( I go grab a cup-of-joe ) , then I plug the USB f/d into a USB port.

Here is where I`m stuck !! , I know stupid me , but what keys do I press to allow the USB drive to boot ?

If I did this I would need to get back to disc utilities to re-format the main drive and do a custom install.

Any and all help would be greatly appreciated , thanks in advance.

In the "old days" you could just but your install disc in and hold the "C" key,
then go to D-U to reformat and clean install.

Take care , Happy Holidays

Gary 

 

[simsaladimbamba]

Here is where I`m stuck !! , I know stupid me , but what keys do I press to allow the USB drive to boot ?

The OPTION key.

Sorry but i don't understand, what external image? I only got dmg file.

The DMG is an image, a Disk ImaGe, that is the one you select.

 

[Jedi]

Thanks , the Option Key

More later

Gary 