Bugs & Fixes: Trouble With USB 'smart' Flash Drives

The next generation of USB flash drives are here--or so the ads claim. Actually, the drives arrived a year or so ago. They are called U3 Smart drives and they offer some admittedly nifty features. The problem is these features are only relevant if you are running Windows. Even worse, they pose a major nuisance if you are running Mac OS X.

In brief, if you have a U3 Smart flash drive (as is the case for many current flash drives, especially those from SanDisk) and use Windows, you can set it up so that, when you insert the drive into a PC other than your own, it temporarily "takes over" the PC. The result is that you can open documents you've stored on the flash drive using special application software also on the drive. This could give you at least limited access to your documents--even if the temporary PC doesn't contain the applications normally needed to open the documents. You can similarly access your Web browser bookmarks. The smart flash drive does this all almost automatically--without modifying any files on the host PC's hard drive. This could be a big help if, for example, you are forced to use a borrowed PC while yours is in for repair. (U3's Web site offers more details on how all of this works.)

I purchased one of these U3 Smart drives, a 4GB SanDisk Cruzer, to test out how well it functioned on a Mac. I understood that I would not be able to use any of the U3 Smart software. I just wanted to see whether I could use the flash drive as a basic storage device.

The initial results were not good. The drive mounted just fine and appeared in the Finder. However, it mounted as a read-only drive. I couldn't modify the contents of the drive in any way!

Note that the Mac says that the flash drive has "Zero KB available.""No problem," I said to myself, "I'll just go to Disk Utility and reformat the drive. All will be well."

Unfortunately, all did not go entirely well. When I launched Disk Utility, the SanDisk drive showed up as a single volume, in MS-DOS (FAT) format and with a Master Boot Record Partition Map. I clicked the Partition button and selected to repartition the drive, using the Mac OS Extended (Journaled) format and the Apple Partition Map option. Choosing these options assumes you never plan to use the drive with a computer running Windows (as is commonly the case for Mac users).

It worked. Sort of. As you can see to the right, Disk Utility (and the Finder) now listed two separate volumes for the flash drive. The first was a 3.8GB partition that was writable and otherwise Mac-friendly. The second was a 60.4MB partition named "U3 System." This partition was still listed as Read Only; it has a CD icon and a CD Partition Scheme.

At this point, I could ignore the near trivial loss of the 60MB partition and start using the flash drive's remaining 3.8GB, just as I would any other flash drive. However, I was determined to get rid of the pesky U3 System partition. As a result, I still had some heavy lifting to do.

I started by trying to reformat the partition via the diskutil command in Terminal, as some reports on the Web had recommended. It didn't work for me.

As a last resort, I turned to the U3 Smart uninstall software available on the Web. The software is Windows-only. So I started up my Intel-based Mac in Windows. From here, I downloaded the SanDisk Launchpad Removal Tool. Note: For other brands of U3 Smart drives, go to this Web page for the needed uninstall software.

The Removal Tool worked perfectly. After returning to Mac OS X, the U3 System partition was at last nowhere to be found! I repartitioned the flash drive in Disk Utility, giving it the Mac-friendly format and partition map schemes. Done. Note: If you plan on using this Tool, ideally do so before trying any reformatting from Mac OS X; this can avoid problems that some users have otherwise reported having.

Despite this success, I can't imagine that the typical Mac user, seeking a USB flash drive, will want to bother with any of this. My advice is, if at all possible, avoid these U3 Smart drives. You'll be happier with the good ol' dumb ones.

This story, "Bugs & Fixes: Trouble With USB 'smart' Flash Drives" was originally published by Macworld.

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