March 4, 2005

Shuffle Raid wrapup

This looks to be my final wrapup on the iPod Shuffle RAID article I wrote a few weeks back that drew so much attention. Included are some final notes on installing OS X to a Shuffle, USB hub observations, and some USB 2.0 PCI card notes.

First, some comments on USB hubs. I received several questions from readers on why certain USB hubs were rejected, As several reviews of the iPod Shuffle have noted, the total width of the Shuffle is a tad larger than the average USB cable connector, consequently it has a tendency to block adjacent ports which are mounted side by side horizontally. Ports mounted vertically present less of an issue as the height of the Shuffle isn't significantly greater than a standard USB connector plug.

So, the main choice in hub selection was one where the ports were separated far enough to allow multiple Shuffles to be plugged in without interfering with each other, the cool look of what I ended up with was pure coincidence.

Next on the USB front, USB 2.0 PCI cards. I investigated several cards from a range of vendors, from the well known Mac vendors (Belkin, Keyspan, D-Link) and other no-name PC type companies, in all cases, what I found was that while I could find PCI cards with as many as 5 ports on a card, in each case these ports were all part of a single common bus. To put it another way, the cards featured a single USB 2.0 port connected to a USB 2.0 hub. So despite the fact that the cards featured multiple ports, each connected device would still be sharing a common bus.

In the case of a Shuffle RAID, I do not believe that any significant speed boost would be seen by using a card with multiple ports versus simply using a hub as I did originally. Some benefit 'might' be seen by putting some Shuffles on the Mac's internal USB bus, and others on a PCI USB card's bus, but I'm not convinced that even 4 Shuffles would saturate the bus sufficiently to slow data transfer by a noticeable amount.

Finally, installing OS X to a Shuffle. The Installer prevents this, it's apparently smart enough to know that the Shuffle can't be a boot device, so this choice isn't even offered. Reformatting the Shuffle (done automatically when it becomes part of a RAID set) doesn't help, and though there are some tricks that will apparently force the Installer to install onto 'other' drives, I don't believe that this would have made any difference.

Several folks suggested using Carbon Copy Cloner, an excellent utility for duplicating drives (among other things), to mirror a working boot drive to the Shuffle. This method would have involved creating a drive that was sufficiently slimmed down to fit onto a 4 Shuffle array.

Unfortunately, getting my original group of 4 Shuffles back together in one spot proved exceedingly difficult, so instead I used a utility called BootCD, a very clever bit of software that will strip out the essential bits of the OS in order to create a bootable CD containing OS X, the Finder, etc. So, I created an image weighing in at about 650Mb containing Mac OS X 10.3.5, and copied this back to a single Shuffle, reformatted as a Mac OS Extended partition.

Startup Disk now saw this drive as an available choice to boot from, but oddly prevented me from selecting it as my boot drive. The icon for the drive would highlight, but the system would beep at me each time I did this, selecting any other valid boot drive did not result in this same beep. Also, quitting from Startup Disk and rechecking settings revealed that this setting was not being preserved, and rebooting the Mac showed that this was in fact the case.

The final trick of holding down the Option key at Startup to select the boot drive resulted in the system hanging, apparently the OS just didn't know how to deal with a Shuffle that had an OS installed onto it. After a few minutes of waiting for the system to finish scanning for boot drives, I finally shut it down.

So ended the search for a bootable iPod Shuffle. However, several folks wrote about the possibility of using such a RAID as a way to secure data so that it could not be recovered without all Shuffles being present. Perhaps some secret documents could be stored on such a RAID, and several people given a Shuffle so that only this group could meet at some other location to recover the data (think James Bond or some form of corporate intrigue). This would obviously not need to be done with Shuffles, any similar Flash media would suffice.

One other reader pointed out that this may actually be the record for the world's smallest (physically) RAID array (cool!), but again since this could be done with any USB Flash device, it wouldn't take much for someone to throw one together about half again this size.

Finally, I'd like to thank all the thousands of folks around the world that visited my site, some to marvel at what I had done, others to simply marvel at the photos of 4 iPod Shuffles all in the same place at the same time. To all of them I'd simply like to say, stay creative, and keep Thinking Different.

Posted by Jim at March 4, 2005 11:10 PM | TrackBack