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I'm having problems installing Lion onto a USB drive.

On a Lion MacBook Pro I saved the 'Install Mac OS X' application, ran it and selected the USB drive as the destination of the install.

A few minutes into the process the machine reboots and comes up with a 'No Entry' sign.

All I can do after that point is a NVRAM reset and then boot back into the OS of the machine. When I look on the USB drive there is a 'Mac OS X Install Data' folder with about half a dozen files.

The USB drive is formatted as 1 partition, Mac OS X Extended (Journaled), GUID Partition Table. Under Get Info -> Sharing & Permissions, Ignore Ownership on this volume is un-checked. I have tried two different brand of drives: an Integral 16G and a Kingston Data Traveller 16G.

I guessing that what I'm trying to do should work - do people agree? Any ideas on where I might be going wrong?

(just to clarify, I'm not trying to create an USB install disk, I want to actually run OSX from the USB disk)

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Provided the USB drive is >8GB (16GB to be safe), and formatted according to the instructions in the link below, the process should work as you want it to. How did you format the thumbdrive? – DrGuyBH Mar 30 '13 at 14:42
I agree, this is supposed to be a size or format problem. It worked perfectly fine for me using a 64 Gb flash drive – bluewoodtree Mar 30 '13 at 15:52
thanks for the suggestions, yes I had formatted the drive according to those instructions. I'll add some more detail to the question to clarify. Good to know it can be done, at least! Maybe I'll try a different USB drive to see if there is a problem with this one in particular. – Damian Helme Mar 30 '13 at 21:36

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