Prevent automounting volumes in OS X

f you have multiple hard drives connected to your Mac, or maybe you have multiple partitions on a single hard drive, by default, OS-X will mount all those volumes at boot time.

In case you don’t want this to happen, and instead mount one only on-demand, when needed, maybe with Disk Utility, here is what you need to do.

Start by opening the Disk Utility app in your /Applications/Utilities folder. Select the drive or partition you don’t want to have auto mounted and click the info button. Now copy the Universal Unique Identifier string and open the terminal, edit or create the /etc/fstab file and insert the following statement, replacing the UUID with yours of course:

One Reply to “Prevent automounting volumes in OS X”

  1. Thank you for your suggestion, but I carried out the commands as per article (with my TM vol UUID), and simply exited Terminal. Restarted and the Toshiba vols still all mount.

    sudo nano /etc/fstab

    UUID=F92B9E9D-349F-3B57-810C-B241F93F2700 none hfs rw,noauto

    I’m not familiar with Terminal, and didn’t see any way to “Save” the edited file, perhaps that was why nothing changed?

    Do I now need to UNdo what I did?

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