title: Mac Disk Utility
body: <p>In disk utility, I accidentally clicked the up arrow icon next to the volume under external, and the volume disappear. What does the icon does and how can I revert it?
  <a href="https://i.stack.imgur.com/VTOfo.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/VTOfo.jpg" alt="disk utility "></a></p>