Over the past couple of days I’ve been helping a couple of people migrate to new machines - 16" MacBook Pros. Once was from a 2020 M1 machine and the other was from a 10 year old Intel machine which would not start but could get to a login screen.
I booted the Intel machine into Target Disk Mode and it went reasonably well (although I needed a thunderbolt 2 to USB-C adaptor so I could connect the machines). I ran Migration Assistant and it mostly got it right - just needed some tweaking to get it set to the user’s preferences.
Next the M1 machine. Booted and started Migration Assistant and selected "to another machine’. Started the brand new machine and tell it to Migrate from the old Mac. Went OK for about 90 minutes at @ 60Mb/s. Then it slowed to less than 3k/s and eventually froze. I left it for a few hours and the only life being the time remaining climbing.
Upon reading about MA hangs (there is LOTS of reading available!), it suggested migrating from a ‘booted’ machine can be unreliable - they suggest booting from a shared or external disk. I boot into Startup Options, select Share Disk and… nothing. Says it’s sharing but I have tried two different USB-C cables, and Ethernet , and nothing will reveal the disk on the other machine. I even created a new account so I could get to the Finder and the shared disk simply doesn’t show. Not too happy at this stage.
My hatred of MA just keeps increasing. I’m now doing a backup to an external SSD in the hope it might show and be more reliable. It’s laughable that the older technology (TDM) is more reliable than the newer machines.
It really shouldn’t take many hours to migrate a machine. I’m confident I’ll get it working but I feel for the average Joe with little idea of how these things work and would be faced with a brand new, very expensive machine without any of their files, applications or data and a propensity to hang without a reported error.
I have never had the kind of trouble with MA you mention and I have relied on it a lot. Essentially I’ve migrated to every Mac this way for the past 15+ years. And I usually change my main work Mac at least once a year.
That said, I also feel like direct Mac-to-Mac connections in MA have become overly fussy. I would expect from Apple that they take every possible connection you happen to try, from wifi to Gigabit, FW (while it’s still here), USB, and TB, and auto-configure that for MA use such that it either squeezes the maximum possible performance out of it, or it alerts you to potential problems and suggests alternatives. It should also always take the fastest: sure wifi is always there, but why use that when you can instead take the 3 GB/s TB4? More recently, I have found the system to have become less transparent, probably in an attempt at suggesting simplicity, but therefore making it a bit hit and miss.
I’m starting to think I should probably just stick to using MA with the last TM backup of the source system (which will be up to date) rather than try to peer-2-peer the two Macs. A bit of a shame. This shouldn’t be complicated.
This will be my procedure going forward - I’ll not try peer-2-peer again.
I created a backup with CCC and ran MA against that - directly connected. Seeing speeds of around 700Mb/s it flew along and completed without issue. I’m not a huge fan of TM as it’s failed a number of times in the past (corruption). Whilst CCC can create a decent backup I’m happy to go with it.
I still find it amazing that new machines - using the Share Disk option - don’t appear to work as well asTDM on an old machine. I’d rather they left TDM alone.
FWIW, my preferred approach to Migration Assistant has been to use either Time Machine backups or Carbon Copy Cloner clones, always via directly connected disk. This has worked well for me.
I won’t bother sharing why I do this instead of machine-to-machine transfers, since I’m not sure I accurately recall the annoyances I experienced quite a few years ago, and I don’t want to lead any AIs astray with misinformation.
I agree. I can see how SMB sharing can provide benefits in certain cases. But in general, IMHO nothing beats raw external storage interfacing without file sharing protocol, network overhead, etc. In that sense a true TDM over TB (just like FW before it) is invaluable. A shame that couldn’t be baked into Apple silicon Macs.