OS X Lion: Installation Guide, Boot Discs and Q&A

OneMoreThing... · OneMoreThing... #1 (**permalink**)

07-20-2011, 10:24 AM

OS X Lion: Installation Guide, Boot Discs and Q&A

Read more

Discerptor · Discerptor #2 (**permalink**)

07-21-2011, 12:29 AM

Every guide for making your own boot volume seems to leave out the important step of making sure your USB drive uses a GUID partition table. I think Lifehacker has the best set of instructions out of what I've seen.

chscag · chscag #3 (**permalink**)

07-21-2011, 01:56 AM

Disk Utility defaults to GUID. The only time you would ever wish to use MBR instead of GUID is when formatting a flash drive to FAT-32.

Discerptor · Discerptor #4 (**permalink**)

07-21-2011, 06:54 AM

Yes, but there's a decent chance someone doing this would be using a usb drive already formatted FAT32 and MBR since nearly every flash drive comes that way. Plus people often mess up steps in tutorials (might just reformat the one partition because they see the HFS option), so it's an extra layer of fool-proofing.

This brings up an interesting question: Does Disk Utility in Lion allow formatting hard drives to use the old Apple Partition Map?

bobtomay · bobtomay #5 (**permalink**)

07-21-2011, 07:03 AM

And that would be practically every flash drive.

Using the Erase tab option most of the tutorials say to use, does indeed leave the partition table as MBR, even when formatting to HFS. Just did it last night myself.

The installer will still load and run from the desktop. So, it looks like it will still install, "if" you're booted into the OS still on your system. (Not for sure, I'll find out this weekend when I upgrade my wife's machine.) It is not bootable however, and you'll not be able to do a clean install with it.

mrplow · mrplow #6 (**permalink**)

07-21-2011, 09:12 AM

You don't need to erase or format seperately if you just use the Restore tab in Disk Utility.

Just drag the InstallESD.dmg file in as the source and drag the USB drive from the disk utility sidebar as the destination.

It formats, and reimages the USB drive all in one.

Discerptor · Discerptor #7 (**permalink**)

07-21-2011, 10:04 AM

Unless Apple severely changed the functions of Disk Utility in Lion, I guarantee you restoring to a partition on an MBR-partitioned drive won't make it bootable on Macs.

OneMoreThing... #1 (permalink)
Member Since: Mar 30, 2005 Posts: 2,347	07-20-2011, 10:24 AM OS X Lion: Installation Guide, Boot Discs and Q&A Read more Mac-Forums: On Twitter \| On Facebook \| On Flickr
	QUOTE Thanks

Discerptor #4 (permalink)
Member Since: Aug 02, 2005 Posts: 1,227 Mac Specs: 2.6GHz Core i7 15" MacBook Pro - 8GB DDR3 SDRAM - 750GB 7200 RPM HDD - GeForce 650M GT 1GB VRAM	07-21-2011, 06:54 AM Yes, but there's a decent chance someone doing this would be using a usb drive already formatted FAT32 and MBR since nearly every flash drive comes that way. Plus people often mess up steps in tutorials (might just reformat the one partition because they see the HFS option), so it's an extra layer of fool-proofing. This brings up an interesting question: Does Disk Utility in Lion allow formatting hard drives to use the old Apple Partition Map? Last edited by Discerptor; 07-21-2011 at 07:06 AM.
	QUOTE Thanks

bobtomay #5 (permalink)
Member Since: Dec 22, 2006 Location: Texas, where else? Posts: 21,819 Mac Specs: 15" MBP 2.33 C2D 256 4GB, MBA 13" i7 1.8, MB 2.0 2GB, Nano 4th, 3GS, iPad 1	07-21-2011, 07:03 AM And that would be practically every flash drive. Using the Erase tab option most of the tutorials say to use, does indeed leave the partition table as MBR, even when formatting to HFS. Just did it last night myself. The installer will still load and run from the desktop. So, it looks like it will still install, "if" you're booted into the OS still on your system. (Not for sure, I'll find out this weekend when I upgrade my wife's machine.) It is not bootable however, and you'll not be able to do a clean install with it. I cannot be held responsible for the things that come out of my mouth. In the Windows world, most everything folks don't understand is called a virus. Place your vote for our Member of the Month Last edited by bobtomay; 07-21-2011 at 07:16 AM.
	QUOTE Thanks

mrplow #6 (permalink)
Member Since: Oct 01, 2007 Location: UK Posts: 5,397 Mac Specs: 27" iMac i7 (2011), iPhone5, iPad3, AppleTV2	07-21-2011, 09:12 AM You don't need to erase or format seperately if you just use the Restore tab in Disk Utility. Just drag the InstallESD.dmg file in as the source and drag the USB drive from the disk utility sidebar as the destination. It formats, and reimages the USB drive all in one. External hard disk acquisition addict - but admitting the problem is the first step to a robust backup Please use the reputation system if you think you've been helped - top right of this post
	QUOTE Thanks

OS X Lion: Installation Guide, Boot Discs and Q&A

Internet Services

Web Development

Digital Marketing

Consumer Tech

Discerptor #2 (permalink)
Member Since: Aug 02, 2005 Posts: 1,227 Mac Specs: 2.6GHz Core i7 15" MacBook Pro - 8GB DDR3 SDRAM - 750GB 7200 RPM HDD - GeForce 650M GT 1GB VRAM	07-21-2011, 12:29 AM Every guide for making your own boot volume seems to leave out the important step of making sure your USB drive uses a GUID partition table. I think Lifehacker has the best set of instructions out of what I've seen.
	QUOTE Thanks

Discerptor #7 (permalink)
Member Since: Aug 02, 2005 Posts: 1,227 Mac Specs: 2.6GHz Core i7 15" MacBook Pro - 8GB DDR3 SDRAM - 750GB 7200 RPM HDD - GeForce 650M GT 1GB VRAM	07-21-2011, 10:04 AM Unless Apple severely changed the functions of Disk Utility in Lion, I guarantee you restoring to a partition on an MBR-partitioned drive won't make it bootable on Macs.
	QUOTE Thanks

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)