I did a clean install of MacOs today, and when choosing where to install it chose "Macintosh HD". It now seems there is a new "Macintosh HD - Data" partition, where MacOS currently references, as well as my old "Macintosh HD - Data" with all my data still there.

Assuming I don't need any of the data on it, is it safe to delete the old -Data partition?enter image description here

EDIT: diskutil list returns the following:

/dev/disk0 (internal, physical):
#:                       TYPE NAME                    SIZE       IDENTIFIER
0:      GUID_partition_scheme                        *500.3 GB   disk0
1:                        EFI ⁨EFI⁩                     314.6 MB   disk0s1
2:                 Apple_APFS ⁨Container disk1⁩         371.0 GB   disk0s2
3:       Microsoft Basic Data ⁨BOOTCAMP⁩                128.0 GB   disk0s3
4:           Windows Recovery ⁨⁩                        920.6 MB   disk0s4

/dev/disk1 (synthesized):
#:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      APFS Container Scheme -                      +371.0 GB   disk1
                                 Physical Store disk0s2
1:                APFS Volume ⁨Macintosh HD - Data⁩     269.1 GB   disk1s1
2:                APFS Volume ⁨Preboot⁩                 634.7 MB   disk1s2
3:                APFS Volume ⁨Recovery⁩                1.2 GB     disk1s3
4:                APFS Volume ⁨VM⁩                      2.1 GB     disk1s4
5:                APFS Volume ⁨Macintosh HD - Data⁩     42.1 GB    disk1s5
6:                APFS Volume ⁨Macintosh HD⁩            15.1 GB    disk1s7
7:              APFS Snapshot ⁨com.apple.os.update-...⁩ 15.1 GB    disk1s7s1

diskutil apfs listVolumeGroups returns the following:

APFS Container (1 found)
+-- Container disk1 9A012B72-C05A-43FB-9A22-F7DC25CC2E05
    +-> Volume Group 94245471-6F9F-3BB6-A6B7-37F3B9A771D5
    |   =================================================
    |   APFS Volume Disk (Role):   disk1s1 (Data)
    |   Name:                      Macintosh HD - Data
    |   Volume UUID:               94245471-6F9F-3BB6-A6B7-37F3B9A771D5
    |   Capacity Consumed:         269121105920 B (269.1 GB)
    +-> Volume Group A7914E12-F1B5-415F-A537-6942D294B6E8
        APFS Volume Disk (Role):   disk1s5 (Data)
        Name:                      Macintosh HD - Data
        Volume UUID:               A7914E12-F1B5-415F-A537-6942D294B6E8
        Capacity Consumed:         42299822080 B (42.3 GB)
        APFS Volume Disk (Role):   disk1s7 (System)
        Name:                      Macintosh HD
        Volume UUID:               5ABDE43A-2F43-414F-8BCE-1AA92D42D887
        Capacity Consumed:         15050797056 B (15.1 GB)
  • So you didn't erase the drive before you reinstalled the OS. Feb 12 at 7:52

It’s important to be certain that you’re deleting the correct data volume since they’re named identically:

  1. In Terminal run the following command: diskutil apfs listVolumeGroups.
  2. Find the volume group that contains both a System and a Data disk. That’s the one you’re going to keep.
  3. The remaining volume group, which only has a Data disk, will be erased. Verify its name (“Macintosh HD - Data”). Note its device node (it will look like disk8s9 except the 8 and 9 will be different). Be sure to be VERY careful about writing this node down exactly.
  4. Run the following: sudo diskutil apfs deleteVolume diskXsY, replacing the X and Y with the actual device node from Step 3. Again, be very careful with your typing here.
  • Great, thank you. I assume it's also ok (equivalent?) to delete it within disk utility as long as the device node matches? @pion
    – sterlingr
    Feb 12 at 16:44
  • @sterlingr: Yes it is :) Also, for completeness, would you paste the output of Step 1 into your question?
    – pion
    Feb 12 at 17:19

Yes, it is safe to delete it if you no longer want the data stored in it.


Mac OS (that is, Disk Utility.app) will warn you if you try to delete half of a volume group. so if you get a warning about deleting the volume you want to delete and another one, you have chosen the wrong volume. If you delete the actual old volume that is fine, as TJ said, as long as you are sure you do not need any of that data.


The Data partition is where the user-files are. You will not be able to get rid of the partition. You can delete the files if you want, but it will delete your preferences, etc.

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .