Opinions on transitioning from old Mac to new

So I’m contemplating replacing my trusty 2013 13" MBP with a new 14" MBP once Apple launches it in the hopefully not too distant future. Two issues I’d be curious to hear opinions on.

1) Continue to use old TM backups or start new TM backups? There are simple instructions to continue using old TM backups with a new Mac (it’s an old link but I’ve confirmed the method still works). The advantage is added convenience because I don’t need a new disk (old TM disk too small to comfortably hold separate old and new TM backups), which means I don’t need to swap disks when I want to fetch an old copy of a file. The cost of the new disk is not really an issue, the convenience is. Is there any real negative to just fudging the old TM backup to continue accepting backups from the new Mac?

2) Which is the best interface to migrate over from old Mac (USB3 & TB2) to new Mac (TB3 only)? I have a TB2 Gigabit adapter and I wasn’t necessarily planning on buying a TB3/USB-C Gigabit adapter because I also already have a TB3/TB2 adapter so I could use the old Gigabit adapter with the new Mac in the very rare instances I need to do that. But if I now need to use Gigabit to connect these two Macs as the fastest transfer method I’d just get a second Gigabit adapter. Any better/faster options for migration than Gigabit?

If it were me:

  1. I’d take over the old Time Machine backups, but you may not need to follow that old tip. Time Machine keeps nagging me to inherit the old Time Machine backup when it’s attached to a new machine, so that may happen for you as well. Partly this is worth doing because it’s always easy to restart the Time Machine backups if you sense anything dodgy going forward. I would do some tests to make sure you can get to old and newly backed up files shortly after inheriting it.

  1. I’d definitely go for Thunderbolt 2. At least in theory, it’s 20 Gbps versus USB 3.0’s 5 Gbps. Of course, if it doesn’t work, USB 3.0 should work fine.

Thanks, @ace. Nice to see that TM offers to migrate to a new Mac. :slight_smile: Assuming nothing bad is known to come from that, that seems to be the easiest route.

I’m a bit surprised about your answer to the port question. Can MA use USB directly? I thought the USB protocol uses a host/client model so that you cannot hook up two hosts together over USB (hence A vs. B type plugs). How would you connect two Macs over USB? Do you guys have A-A or A-C cables just lying around? I don’t have a TB2-TB2 cable lying around (I do for my dock at work, but I can’t go there right now due to lockdown) so I would have to buy one, but then I might as well just get a $10 USB-C Gigabit adapter and use the TB2-Gigabit adapter I already have for my old Mac. Unless of course anybody here knows something faster or cheaper or more convenient.

  1. Time Machine–I have usually simply updated the Time Machine on my new Mac when I have replaced a Mac. That is true for both my current Macs (iMac and MacBookPro). However, when I upgraded from Mojave to Catalina, I ran into difficulties in updating the Time Machine. For both machines, the first attempt to do so failed, probably due to running out of memory and paging space. Eventually, the MacBook Pro update ran, but I went from having at least 12 months archived to having about 4 months archived. On my iMac, the process failed and I just created a new Time Machine under Catalina. Note that subsequent Time Machine runs on both systems now run faster.

  2. I have always (with one exception) migrated from hard drive clones created with Carbon Copy Cloner or SuperDuper. Note that SuperDuper does not require payment in order to create a full (as opposed to incremental) clone. My current backup hard drives are all USB-3, and I use an adapter cable or an adapter hub to connect to my 2018 MacBook Pro. I think that the primary limiter of the speed is the data transfer rate of the drive, so I’m not concerned about the slower interface. I would advise that for your new MacBook Pro, you obtain a small USB-C hub like those recommended on the Wirecutter. You will be able to use it to work with legacy drives, HDMI devices, camera cards, and obtain full Ethernet speed. I keep one in the travel bag for my laptop.

Doh! Of course. I’ve been dealing only with external drives so didn’t parse the issue as being for Migration Assistant between two Macs. As @aforkosh says below, though, you can just migrate from bootable duplicate if you have one. So yeah, the Gigabit Ethernet adapters are probably a better try.

Of course, given that migration happens only once, it’s not the end of the world if you have to do it over a slower connection.

Thanks, @aforkosh. After reading what you wrote I wonder if I should get a brand new HDD and start TM over from that with the new Mac just to keep things clean and tidy. I haven’t had actual issues with my older TM drives, but I do know that there have been instances where I’ve felt backups take excessive amounts of time or the drive took quite a while to finally eject. Maybe a fresh start wouldn’t be a bad thing. With a brand new 2 TB WD Green drive for $48 on Amazon I’d feel tempted.

Thanks, @ace. It seems both you and @aforkosh don’t migrate directly from the older Mac, but from its clone. Since I’d be cloning the older MBP before I migrate anyway that’s certainly a viable option. I have a fast USB3 SATA dock so cloning to/from disks is quite fast.

Does anybody know if there’s any difference in terms of reliability if you have MA get data from another “live” Mac vs. from a clone disk? Does anybody even use the direct migration from another Mac anymore? I remember using it over Gigabit and FW a couple times, but that was a long time ago.