APFS - "Data" Partition

[redAPPLE]

hello.

i just noticed something.

checking my storage drive in disk utility, it shows that i have 2? partitions. one is macintosh hd and the other is macintosh hd - data.

the drive is configured as an APFS drive. is this normal, that a "data" partition is automatically created?

 

[casperes1996]

Yes, and you're using it actually. The OS generally makes this transparent, outside of disk utility and similar tools, but the main Macintosh HD volume is actually read-only and just for the OS and core stuff. Everything you add to your computer happens on the Data partition. It's a security mechanism

 

[redAPPLE]

Yes, and you're using it actually. The OS generally makes this transparent, outside of disk utility and similar tools, but the main Macintosh HD volume is actually read-only and just for the OS and core stuff. Everything you add to your computer happens on the Data partition. It's a security mechanism

thanks for the reply.

so should want to sell the mac in the future, do i need to erase „both“ partitions?

maybe you have a link where this is explained?

 

[casperes1996]

thanks for the reply.

so should want to sell the mac in the future, do i need to erase „both“ partitions?

maybe you have a link where this is explained?

You need to erase the higher level device - In Disk Utility, go to the View menu and pick "Show All Devices" - Show Only Volumes is default. Then you can pick the hard drive/SSD and erase that instead of either of the volumes.

About the read-only system volume in macOS Catalina

macOS Catalina runs in a read-only system volume, separate from other files on your Mac. When you upgrade to Catalina, a second volume is created, and some files may move to a Relocated Items folder.

support.apple.com

There's a little from Apple's own page about it, though it's not really super detailed about the reasons for why it's done, and it makes it seem a bit scarier than it actually is - Most locations are still writeable because they will be mapped to the data volume transparently