I have two virtual disks:

  1. Main macOS disk
  2. Bootcamp windows disk

When I use diskutil listin command line, it shows me:
enter image description here

So what the /dev/disk1 is? Should I delete it? And what is EFI EFI disk0s1 is?
P.S. No fusion drive, only one SSD physical drive.

2 Answers 2

  1. The internal virtual disk is a Logical Volume and part of a CoreStorage Logical Volume Group. CoreStorage itself is a logical volume manager similar to Linux' LVM. An LVM is an additional abstraction layer in between hard disks and partitions on one side and volumes on the other side.

    In macOS you can convert a partition (e.g disk0s2) with a HFS+ file system lossless to a Logical Volume Group which initially contains several nested items: a Physical Volume, a Logical Volume Family and a Logical Volume. The final Logical Volume is slightly smaller than the original partition, because CoreStorage needs some space to save administrative data.

    The Logical Volume contains the data of the previous standard volume/partition and is mapped to its own (virtual) disk device: disk0s2 > disk1

  2. EFI system partition - Usage - macOS:

    On Macintosh computers based on Apple–Intel architecture, the EFI system partition is initially left blank and unused for booting. However, the EFI system partition is used as a staging area for firmware updates.

None should be deleted!


It's your macOS partition, the physical partition at /dev/disk0s2. i.e. the physical partition /dev/disk0s2 is the virtual disk /dev/disk1. You can confirm that by running mount in Terminal (or similar) - it should show /dev/disk1 mounted as /, e.g.:

/dev/disk1 on / (hfs, local, journaled)

And do not delete it!

EFI is, if I understand correctly, the boot partition.


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