first aid high sierra volume could not be unmounted

The big difference in the volume layout is that disk1s1 and disk1s2 form a Volume Group, within the bootable container disk1 on your boot disk disk0. the writable Data volume, by default on the internal disk named Macintosh HD – Data, which is normally hidden from view at /System/Volumes and accessed via firmlinks,.

the read-only System volume, by default on the internal disk named Macintosh HD, which forms the root of the boot file system,.

If that fails, the only alternative source of recovery tools is Remote or Internet Recovery, entered with the Command, Option and R keys held.Ĭatalina changes that by splitting the startup volume into two:

VM, containing virtual memory caches, which is upwards of 20 KB depending on use.īecause some boot disks, notably Fusion Drives, don’t support APFS in High Sierra, some continue to use HFS+, in which case those are instead HFS+ volumes, which can’t be inside a container.Įach boot volume group has only one Recovery Volume, booted by holding the Command and R keys during startup.

Recovery, the Recovery Volume, of around 500 MB,.

Preboot, a small volume of around 40-50 MB,.

the startup volume, by default on the internal disk named Macintosh HD, which forms the root of the boot file system,.

Within the latter are a minimum of four APFS volumes: For example, a Preboot volume shown here as having an identifier of disk7s3 could be anything from disk7s1 to disk7s7 instead, and when in the container disk3 would be anything from disk3s1 to disk3s7.Ī standard APFS boot disk in High Sierra and Mojave consists of an EFI partition and the main APFS container. Throughout these diagrams, Unix-style identifiers are only examples of what you might see, and will vary in use. This article is an atlas of boot disks from the next step with High Sierra and APFS, to the present in Monterey, with particular reference to Recovery volumes.

When Apple added Recovery Mode, it was kept on a hidden HFS+ volume, and the layout of boot disks started to become more complex.

I suppose its nearest equivalent was single-user mode (SUM), which for many was the preferred way of running fsck to check and repair your startup disk, and didn’t we need to then. Until July 2011, with the release of Mac OS X 10.7 Lion, Macs didn’t have any Recovery Mode.

First aid high sierra volume could not be unmounted