what is snapshot in disk utility?

[James Godfrey]

Hi

I was looking on disk utility last night and I noticed I have…

Macintosh HD
Macintosh HD snapshot

What is snapshot exactly?

Thanks

 

[DeltaMac]

Good info explaining snapshots, related to your APFS boot volume:

Working with macOS Snapshots

Snapshots are a feature of the Mac's APFS file system that allow you to roll back your Mac to a previous state. A good tool to have when you upgrading the OS.

eshop.macsales.com

 

[James Godfrey]

Good info explaining snapshots, related to your APFS boot volume:

Working with macOS Snapshots

Snapshots are a feature of the Mac's APFS file system that allow you to roll back your Mac to a previous state. A good tool to have when you upgrading the OS.

eshop.macsales.com

Ah ok I see, so will the snapshot eventually disappear or does it have to be manually deleted?

 

[DeltaMac]

If you think you have a reason to delete a snapshot, or all shapshots, you can remove it using Disk Utility.
Otherwise, it is simply a part of how the system operates.
Are you running low on space on your boot drive (why do you ask?)?

 

[James Godfrey]

If you think you have a reason to delete a snapshot, or all shapshots, you can remove it using Disk Utility.
Otherwise, it is simply a part of how the system operates.
Are you running low on space on your boot drive (why do you ask?)?

No I’m not low on space or anything, was more just concerned of why it’s there and if it’s needed, however it seems as though MacOS is using the snapshot when I am using the mac as it says it’s mounted…

 

[gilby101]

Macintosh HD snapshot

The link from @DeltaMac is a good description of APFS snapshots in general. The boot volume is a special case of APFS and its snapshots.

Macintosh HD is the read only system sealed volume (SSV) which is mounted as a snapshot at / forming the base of the file system. On my Intel Ventura system this is 8.8GB (smaller than it was for Monterey). 'Sealed' in SSV refers to it being cryptographically signed by Apple and checked on every boot before being mounted.

For the structure of boot volumes read:

An atlas of recovery and boot volumes: High Sierra to Monterey

From High Sierra’s four-volume group to macOS 12 on Apple silicon with three containers and 11 volumes, and both regular and fallback Recovery volumes.

eclecticlight.co

Ventura volume layout

Updated charts of containers and volumes on boot volume groups for Ventura, with details of cryptexes and what they do.

eclecticlight.co

 

[James Godfrey]

My disk utility looks like this so I presume that’s how it’s meant to be?

 

[gilby101]

My disk utility looks like this so I presume that’s how it’s meant to be?

Yes!