I have erased my macbook HD from the recovery mode (cloverleaf + R at startup) then I have reinstalled mojave from there. I left the mac for the night. Next morning, it was waiting on the country selection, then arrived to the wifi select.

I use a magic keyboard that used to be paired with that mac and it was usable right away.

How is possible the magic keyboard was still paired ? Wouldn't an disk erase and reinstall remove it ?

I am looking to find where and how this pairing is maintained (and possibly review the list of information that has not been removed).

  • Another strange behavior, I turned on firefox sync and got a notification my other computers that a device with the previous network name of that macbook is syncing. Could there be some kind of cache with settings for networking and devices that doesnt get cleaned after a erase/reinstall ?
    – Raphaël
    Apr 19 at 8:22
  • When I open the terminal, I can also see that the hostname is still the macbook name before the erase/reinstall
    – Raphaël
    Apr 19 at 8:55
  • Most probably, it's stored in NVRAM. See the last step in support.apple.com/en-us/HT201065
    – lhf
    Apr 19 at 9:15
  • Thanks, I literally was just reading this. Does Apple disclose how this is technically achieved ?
    – Raphaël
    Apr 19 at 9:21
  • It would have to be in NVRAM - otherwise it couldn't be used to start/wake the Mac before the drive wakes/spins up.
    – Tetsujin
    Apr 21 at 7:24


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