MacOS – how can I fix disk permissions on a headless Mac that won’t boot

macospermission

I've made the mistake of changing the "everyone" permissions for the root of my Mac Mini server's startup drive to "none".

(I believe) this would be fairly easy to fix with the Recovery Partition – except this is a headless server, and I can't locate my Mini-DVI adapter, so I'm monitor-less.

my question is: would it be possible for me to boot my Mini to Target Disk Mode, then connect it to my MacBook, and boot the MacBook from the Mini's recovery partition, to fix the permissions? I'm asking because I don't own the necessary FireWire cable, but I'll buy one if it can fix this issue.

or, possibly, could I repair this using Disk Utility on the MacBook's own drive?

Best Answer

Two options:

  1. You can repair permissions using Target Disk Mode from your MacBook - as you mentioned, you'll need a FireWire or Thunderbolt cable to do so. No need to use the recovery partition on the Mini - you can use Disk Utility on the MacBook to repair the drive on the Mini. In order to use Target Mode on a headless machine that won't boot, hold the 'T' key down during startup.

  2. Alternatively - since you need to buy a cable, you could instead buy an adapter to connect a monitor (if you have one) & repair using the recovery partition on the Mini.

I'd have both options on hand in case of issues. Target Disk Mode will work if you have a keyboard & a FireWire cable.

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