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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 Lion.app' 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? macs.about.com/od/diyguidesprojects/ss/usbflash_3.htm –  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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