Have you ever wondered what the Thunderbolt Bridge device that’s listed among your network adapters actually is? It appeared with Mavericks, and it’s a useful step up for those who are migrating from one machine to another, since it enables disk access from a booted machine’s encrypted partition.
Some of you will know that you can boot up a Mac in what’s called Target Disk Mode, which means that the computer boots from firmware and acts like a large hard disk.
You can connect to it via Thunderbolt or USB from another Mac, then use the lovely Migration Assistant tool to suck everything out of the first Mac and push it onto a new computer. It’s a great tool for when you need to get your life out of one Mac and into another. I wish I could boot up a Windows computer in the same way.
The problem arises if you’ve encrypted the hard disk. Encrypting the disk creates an extra layer of safety and security for your data, especially for a laptop that might be mislaid or stolen.
No-one can recover the data held on that hard disk without the appropriate keys, and those are held in your online Apple account. But what happens when you boot such a machine into Target Disk Mode? There’s no proper OS running, so it can’t decrypt the contents of the hard disk – which is where Thunderbolt Bridge mode comes in.
It allows you to boot the device, get the operating system running (and therefore access its hard disk), then connect to another computer via Thunderbolt to complete the data transfer.
I’m a little nervous at the thought of two computers connected via Thunderbolt, given that it’s effectively PCI Express. However, it clearly works – and it’s the solution for times when you need to transfer a lot of data from one machine to another at high speed.
Thunderbolt fibre cables
I’m finding it frustratingly difficult to get hold of 10m and 30m fibre Thunderbolt cables so that I can move my disk arrays away from my desktop. Sometime soon, if the Gods look kindly upon me and Santa brings me a new Mac Pro, I want to be able to move everything off my desk except for the monitors, keyboard and trackpad.
A critical component of this project is the arrival of fibre-optic Thunderbolt cables from Corning. These were certified by Intel months ago, and I saw them in use at the NAB show in April in Las Vegas, with a promise that production was going to start “real soon now”. Indeed the cables are now available in Apple’s online store in the US – the 10m version is priced at $330 – but not in the UK.
So, I visited a few online vendors in the US to see if they could supply it. Oh yes, said their website, the cables could be with me in a few weeks. Excitedly, I placed an order at one well-known vendor. Twenty-four hours later, I received an email to say the cable has been delayed and might arrive in February 2014. I cancelled the order.
Perhaps Apple is taking all the stock for itself? If so, it would be great if it let the rest of us order it, too. I see from the US Apple website that the cables are now “available to ship in 24 hours”. Now, who do I know with a US credit card and postal address?
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