Igor Kulman

Preventing Windows drives from getting automatically mounted on macOS

· Igor Kulman

If you run macOS side by side with Windows or have some drives formated with NTFS, you may not want them to get automatically mounted when you start macOS. I have a Windows 10 SSD with NFTS and a data HDD with NTFS next to my macOS SSD and I do not use any o those two drivers when booted in macOS, so I was looking for a way to have them not mounted at startup.

The main reason for this other than them not being shown in Finder is that macOS spins the data HDD from time to time for no apparent reason and I really do not want this.

In a classic Linux system you could edit /etc/fstab. This file can be also created on macOS, but Apple does not recommend editing it directly but to use sudo vifs. The drives should be addressed by their UUID as opposed to their “location” on Linux, so you first have to find that UUIDs.

When you have the drivers mounted, run diskutil info /Volumes/"Volume name" | grep 'Volume UUID' where “Volumne name” is the volume name as shown in Finder. This will get you just the UUID.

Next you need to create a new record for each of the drives you do not want mounted at startup in /etc/fstab (by running sudo vifs as mentioned before) in this format

UUID=XXXXXXXXXXXXXXXXX none ntfs ro, noauto

where “XXXXXXXXXXXXXXXXX” is the correct UUID, ntfs is the filesystem and ‘ro, noauto’ means the drive will no be mounted automatically but when you mount it manually it will get mounted read-only.

The resulting configuration may look like this

# Warning - this file should only be modified with vifs(8)
# Failure to do so is unsupported and may be destructive.
UUID=8CCC7F74-CB0B-44BE-A423-FEA4B8314646 none ntfs ro,noauto
UUID=82D51380-0E13-4B98-8CEB-B87715F82056 none ntfs ro,noauto

See also