Do not show a volume in finder (MacOSX)

 From https://www.idownloadblog.com/2016/12/02/how-to-hide-mounted-volumes-from-desktop-finder/

1) Ensure the volume that you want to hide is mounted and visible in the Finder, desktop, or Disk Utility.

2) Make a note of the chosen name of your volume, for example, Time Machine or Storage.

3) Launch Terminal and type the following command, replacing “Drive Name” with the name of your own volume, which you noted earlier (keep the quote marks):

sudo SetFile -a V /Volumes/"Drive Name"

4) Enter your password when prompted.

Note: Install command line developer tools if you’re prompted to do that.

5) In terminal: killall Finder

To revert :

sudo SetFile -a v /Volumes/"Drive Name"

killall Finder