USB Thumb Drive Won't Do HFS+ Format

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I've been trying to format a 128 GB USB thumb drive as a Mac OS Extended volume (HFS+) but it silently fails and the only successful format I can do is MS-DOS FAT. As I want to use the drive to install a dev version of Lion, I need the HFS+ format and trying it in terminal gave the following result:

Marks-MacBook-Pro:~ markbyrn$ diskutil eraseDisk HFS+ lion disk1
Started erase on disk1
Unmounting disk
Creating the partition map
Waiting for the disks to reappear
Formatting disk1s2 as Mac OS Extended with name lion
Initialized /dev/rdisk1s2 as a 128 GB HFS Plus volume
Mounting disk
Could not mount disk1s2 with name (null) after erase
Finished erase on disk1
Marks-MacBook-Pro:~ markbyrn$

So it appears to initialize but won't mount. I also tried partioning the drive into 2 or 4 partitions and formatting an individual partition but that didn't work either.

I have installed the dev version (preview 2) of Lion on a 16 GB thumb drive but there's not enough free space to do an update to preview 3. Any advice on how I can get this 128 GB thumb drive formatted?
 

bobtomay

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Have never formatted a thumb drive, so I'm only shooting in the dark here.

Try giving it a name instead of leaving it blank.

Possibly try the Partition tab instead of the Erase tab. Maybe make sure you've gone into the Advanced menu and selected GUID partition type.

As I said - only guessing here.
 
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Maybe make sure you've gone into the Advanced menu and selected GUID partition type.

I had already tried your other suggestions but with respect to the quote, how do one get to this "advanced" menu or is it the Options menu with the 3 choices (GUID, Apple Partition, Master Boot)? I already tried the latter with GUID selected but still doesn't work.
 

bobtomay

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Yep, that was it.

Hopefully someone will come along that's done this and give you a lead.
 
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As luck would have it, I have done this. :) Here's a good guide on how to properly format a flash drive in preparation for installing OS X to it:
Format Your USB Flash Drive for Use With OS X

BTW… if this doesn't work for any reason, please post back with the exact model of thumb drive you have.
 

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That's good info, especially the part about changing ownership. Since I've never done the procedure, I probably would have never thought of that.

Thanks.
 

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