Last Week on My Mac: Migration is like blisters

I normally only try migrating to a new Mac once every three or four years. In the next week or so, I will be sharing my experiences and trying to help you decide how best to do it. As an experience, it reminds me of blisters.

In my first proper job when I had fully qualified as a doctor, I worked for a year as a general practitioner at the Royal Marines basic training establishment. One of the commonest problems we had to deal with every day were blisters, typically of the feet. By far their best treatment, if you can stand it, is application of tincture of benzoin – the dreaded ‘tinc benz’.

This seems to work on the principle that each blister is going to cause a certain amount of pain. You can fiddle around with dressings and such, but your pain will then be spread over days or even weeks. Inject or apply tinc benz, and you get the whole thing over in a couple of excruciatingly intense minutes instead.

Migrating between Macs is much the same. In the past, I have either been denied the option of migration (often because it could never complete) or didn’t bother trying. For days and weeks I was left fixing things which didn’t move across smoothly.

This time, I opted for the tinc benz approach. For a few hours, I was tearing my hair out, wrestling with unwanted updates and turgid iCloud syncs. Once I had driven my way through that intense hassle, I emerged to sweetness and light, and a new iMac Pro which was fully loaded and ready to go. As I wrote at the time, this shouldn’t be the case, and Apple needs to improve migration in both macOS and iOS.

Having relied (for once) on macOS’s Migration Assistant, and a couple of other tricks of my own, the last stage was to hook my new system up to my old Promise Pegasus RAID and get Time Machine running again.

Before I could do that, I needed to give the RAID system a thorough clean. I carefully popped each of its four drives, and removed all the dust and deposits, ensuring it was fully dry before re-assembly. I then hooked it up via Apple’s Thunderbolt 3-to-2 adaptor, and powered it up.

I have no idea how long this Promise Pegasus will last. It’s on its second set of disks now, and coming up to six years old next month. It looks and feels engineered for ever, and my fingers are crossed that it will just keep on going. For the first time, this last summer its accumulated dust had started to cause some issues with cooling. On warmer days, its fan ran up for a few minutes to keep the drives cool, so this was a good time to give it some care and attention.

When I turned Time Machine on to start running my new backups, it invited me to choose whether to run them on from those of my previous iMac, or to treat this as a new computer for backup purposes. I chose the latter, and five hours later all 1.2 TB of my new iMac Pro had been copied into a new backup folder on the RAID.

What was not noticeable during that period was any backup activity. With its eight cores and four Thunderbolt 3 ports, the iMac Pro remained lithe and nimble whilst it poured files down the cable at the RAID. Far from that backup needing to be left to run through the night, I was able to work on as normal throughout.

What did puzzle me when it was complete was that Time Machine then got its bit between the teeth and ran automatic backups every half hour for a while. I have never seen that before, and I don’t know why it should have happened. I watched it carefully using T2M2, and those backups have been hourly, as regular as clockwork, ever since.

My old iMac is now resting upstairs after nearly three years of continuous running. It’s still a lovely system, but even Apple’s Xcode feels lightweight and brisk on its successor. Before you put in a bid for my old iMac, it already has a new home to go to, once I’m completely happy that everything is up and running here. Then I’ll deauthorise it, sign it out of iCloud, format its Fusion Drive, and install macOS Mojave for its next user to enjoy.