The APFS - Data volume

Question

The APFS - Data volume

I was using the public beta of Catalina. When I attempted to downgrade, I noticed the additional [Machine Name] - Data volume that I never noticed before. It has the user directory where all my settings are.

Now that I'm on the official Catalina release, I still see that volume in Disk Utility (not in Finder). It seems to be redundant, or is it not?

What and how did it get created in the first place?

Is it safe to remove the volume?

How to remove it safely?

MacBook Pro with Touch Bar

Posted on Oct 10, 2019 8:31 PM

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Answer 1

Kappy

Level 10

362,001 points

Oct 10, 2019 8:50 PM in response to simplysimpler

Catalina creates two volumes. The visible volume is the System volume. It contains only the set of files required for macOS. These files as well as the volume are write-protected to prevent unwanted changes. The second volume, the invisible one, is where all the user files are located long with Applications. The volume is invisible while the actual files are represented on the System volume using special aliases called hard links.

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Answer 2

Kappy

Level 10

362,001 points

Oct 11, 2019 7:20 PM in response to scb

Are you booted from a Mojave disk when you see the Data volume? If so, it isn't invisible since Mojave uses a different volume structure from Catalina. I have several Catalina bootable disks. I do not see the Data volume on any of them.

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Answer 3

Kappy

Level 10

362,001 points

Oct 11, 2019 8:20 PM in response to scb

Frankly, I don't know. Have yet to come across a Catalina installation in which the Data volume was visible. Certainly, you can try making it invisible although I don't know what method macOS uses. I suspect it may be configured using diskutil via the Terminal.

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