macos-trouble-shooting.md

title	layout
macOS Troubleshooting	page

These solutions have worked for me and are listed here for my personal reference only — if you decide to give any of them a go and they solve all of life’s problems, then great; if they don’t, and something catastrophic happens, then you’ve nobody to blame but yourself.

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macOS

Issue:

• the keyboard shortcut CONTROL + SHIFT + EJECT (put displays to sleep) is no longer available as the keyboard has no EJECT key

Solution:

• CONTROL + SHIFT + POWER

  or

• CONTROL + COMMAND + Q

  (activate lock)

• ESCAPE

  (turn off displays)

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diskutil

Issue:

• the free space on a mechanical hard-drive needs to be securely erased

Solution:

• diskutil secureErase freespace [N] /Volumes/[DRIVE]

  replace [N] with the required value

  replace [DRIVE] with the name of the drive

Comments:

• the following values can be used for [N]:

  • 0 – single-pass zero-fill erase
  • 1 – single-pass random-fill erase
  • 2 – US DoD 7-pass secure erase
  • 3 – Gutmann algorithm 35-pass secure erase
  • 4 – US DoE algorithm 3-pass secure erase

• if the name of the drive contains a space, precede it with \; for example, diskutil secureErase freespace 4 /Volumes/Macintosh\ HD

• further info is available via the macOS diskutil reference guide at s64.com

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RansomWhere?

Issue:

• entries have been added as trusted in error

Solution:

• sudo /Library/Objective-See/RansomWhere/RansomWhere -reset

  (clear user-approved entries and restart the launch daemon)