MacBook – MBP 2017 making high pitched noise when in Target Disk Mode

All non-vintage MacBook Air support target disk mode, including the Apple Silicon based MacBook Air released in 2020.

• https://support.apple.com/en-gb/guide/mac-help/mchlb37e8ca7/mac

Many vintage and obsolete Air still support target disk mode as well. Target Disk Mode is not supported on older Macbook Air that lack a Thunderbolt port. The Mini DisplayPort is purely a video out port, and cannot be used for data transfer, despite the identical connector. Since thunderbolt is far faster than gigabit ethernet, it’s preferred due to speed as mentioned in the comments below.

• https://support.apple.com/guide/mac-help/transfer-files-mac-computers-target-disk-mode-mchlp1443/mac

Any MacBook Air that have Thunderbolt 3 or 2 support target disk mode.

For all devices - regardless of ability to boot to target disk mode, an additional supported option for transferring data between two Macs is using a wired connection and Migration Assistant. Since MacBook Air have no ethernet ports, you will need to purchase the Apple USB to Ethernet Adapter for the older model MacBook Air which does not have a Thunderbolt port, an Apple Thunderbolt to Ethernet Adapter for the newer model which supports Thunderbolt or one of the many third party USB adapters.

If you do not want to purchase the adapters, you could migrate the data off the Air using file sharing or have the Mac opened by a service technician to remove the storage and assist with a converter or another Air to house the drive while it's being accessed.

By deleting all files that are non-essential you can speed up the time of transfer, but the USB to ethernet adapter is 100MB speed and likely the fastest you could transfer files on your Air from 2014 or before. Since 2014, much faster WiFi and Ethernet adapters mean faster transfer speeds than before.

Here's some clarity for anyone looking. The root cause of the sign in when switching the host is that programs often store their license information x'ord (or otherwise encrypted with) a hash of the host hardware. This means that, when the hardware changes, the previously stored configuration is unrecoverable. I've tried spoofing the MAC address, but all programs I test seem to do a deeper hash using the hardware (e.g. system_profiler). I've found a number of workarounds, though:

• Stop using apps from the App Store. While the app store uses this hardware hash technique, many indie programs don't. For those, buying directly works (e.g. Moom)
• Where possible store the license information in an un-hashed version. For example, Sublime Text supports this by editing the license file (see https://forum.sublimetext.com/t/st3-license-not-syncing/11738)
• I've found that the iCloud sign in behavior stopped when I created my own keychain (not the default login) and set it as default. Not using an App Store apps, and using this new default keychain, I get no prompts to log into my iCloud account on start up

After this, some programs that are still offensive are: Office 365, Creative Cloud, and Mathematica. I ended up finally ditching Creative Cloud - I've long switched to other tools, so the one part that I still use (Font syncing), I just downloaded all the fonts locally.

Overall this is pretty good now. After switching hosts, I get zero dialogs to log in. All my main flows work (Thunderbird, terminal, Sublime). Occasionally I have to log in, but much less of an issue than before.

Hope this helps.