Hybrid flash drive: Bootable Mac, but still readable on Windows. Possible?

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Hybrid flash drive: Bootable Mac, but still readable on Windows. Possible?

I love the idea of having a bootable OS X installation thumb drive, but would also like to use another partition on that same thumb drive to transfer files between Windows machines.

A bootable OS X drive must be partitioned GUID Partition Table (GPT) - but every time I've tried to read a FAT32 partition on that drive under Windows (even if I've wiped the drive, and that's the only partition there), it's failed to even see the drive. Very frustrating.

It appears that Windows boxes can only see drives with Master Boot Record (MBR) as the partition scheme; GPT completely stymies most such machines (e.g. photo-printing kiosks in drug stores).

So: Is is possible at all to have a single thumb drive with multiple partitions, which contain one partition which is bootable on the Mac, and another partition which can make files visible to Windows machines?

Posted on May 9, 2012 9:59 PM

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Answer 1

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MrHoffman

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May 10, 2012 7:33 AM in response to Brian Latimer

Which Windows version? Windows 7? Older Windows was limited to MBR. Newer can use GPT for various tasks.

As for the root question, look up the various discussions on hybrid-format MBR disk volumes.

Whether that'll work here, I don't know.

And these days, buying and dedicating a USB stick is a cheap workaround/fix/alternative.

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Answer 2

May 10, 2012 8:54 AM in response to MrHoffman

Glad to hear that newer Windows versions don't suffer this limitation - but I have yet to see a Windows machine in common use in the expected environments, which is running anything beyond XP. Again, my main examples would be photo-printing kiosks in stores, and similar. "Lowest-common-denominator" certainly seems to apply.

And, agreed that flash drives are incredibly cheap - but I really didn't want to carry 2 around, if I could use a single one. I have been investigating possibly using a dual-sided implementation, such as:

http://www.amazon.com/gp/product/B004FPYLHY/

I had seen some references to "hybrid MBR" recently, but they were always accompanied with significant caveats regarding reliability. If you believe this might be worth pursuing, though, I'm game for trying. Any pointers on step-by-step guides to result in a drive in the form needed?

1) Bootable OS X Lion install/recovery partition

plus

2) General data partition (I do not care about bootabillity into Windows)

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Answer 3

May 10, 2012 1:56 PM in response to Brian Latimer

I do not use Windows, nor know whether Windows 7 resolves this case, nor would Apple folks in an Apple forum seem to be the best resource for learning about the support, features and capabilities of the various Microsoft Windows products around GPT and hybrid MBR-GPT volume structures. You have a Windows question, at its core. Can your version of Windows support GPT, or hybrid MBR with GPT, in other words.

From dealing with some folks that use it, Windows 7 is vastly superior to Windows XP.

I would generally not recommend pursuing the hybrid MBR scheme, but that's what you have asked for. Too easy for something to "get creative" or otherwise misfire and end up corrupting something else that you care about. What was linked was a description that'd I'd posted a while back around what's technically involved with a hybrid MBR.

The second key disk is the simplest approach. They're small enough these days that two (whether conjoined from the vendor, or with glue, or united with a split-ring) is little different from one. That's a few dollars, and you're supportable on both platforms.

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