To my knowledge I advise against deleting snapshot
This is reported on other threads which may cause an update issue and require you to reinstall macOS for updates.
See here :
#34 : I quote :
"A word of caution - The Snap Shot partition/volume was created by Apple to enhance Security and to improve how future updates are delivered and installed. Deleting the Snap Shot prevents future OS X updates, many hack users that went the route of deleting the Snap Shot, found that even though the updates were delivered to their machines, they were offered a full install of 11gbs to 12gbs opposed to the incremental update of 3gbs to 4gbs.
The snag comes about because the update looks for the previously installed Snap Shot, when it is not found, the update stalls or only a full one is offered.
This is a cycle best to avoid as you would have to do this each time if that is your inclination. I wrote about this folly sometime back and I am quite surprise people are still opting to delete. If this next statement makes any sense considering I am talking about a non Apple machine, I try my upmost to have a vanilla install as best and close as possible to Apple's offering, I realise that is not always possible as one may have to do a tweak here and there but if it is avoidable, I leave as intended. Hope this helps someone out there but as the saying goes..... 'Every man to his own'."
But the other interest of snapshot :
Snapshots are more efficient than regular backups. If a single byte changes in a file, the whole of that file has to be copied in the next backup. Snapshots keep only the parts of the file that change, so that the original can be reconstructed. But over time and use of that file, the amount of it which has to be retained to restore its original state inevitably rises up to the limit of the whole file size.
If you have sufficient free disk space to include VM and other large files in backups and snapshots, then you don’t need to change their location or policies.
To maintain better control of backup storage, you should move VMs and other large files to a separate volume, and add the whole volume to the Time Machine exclude list, or disable snapshots on that volume in Carbon Copy Cloner.
You can create snapshots at any time. by making use of terminal app , command line tool.
- Launch Terminal,
- To create an APFS snapshot, copy and paste the following command into Terminal at the command prompt:
3. Press Enter or Return on the keyboard.
Terminal responds by saying it has created a local snapshot with a specific date.
The restore begins, and a process bar displays. When the restore is complete, your Mac reboots automatically.
4. You can check to see if there are any snapshots already present with the following command:
INI:
tmutil listlocalsnapshots /
This command displays a list of any snapshots that are already present on the local drive.
How to Roll Back to an APFS Snapshot Point in Time :
Returning your Hack's file system to the state it was in previously using a snapshot requires a few steps that include the use of the Recovery Partition and the Time Machine utility.
Although the Time Machine utility is involved, you do not have to have Time Machine set up or use it for backups, although it is not a bad idea to have an effective backup system in place.
When you have successfully booted into Recovery :
- Select Restore From Time Machine Backup and click Continue.
- A list of disks connected to your Mac that contain snapshots (and Time Machine backups) is displayed. Select the disk that contains the snapshots — this is usually your hack's startup disk — and click Continue.
- Select the snapshot you want to restore from the list of snapshots. They are sorted by date and the macOS version in which they were created. Click Continue.
- A drop-down window asks if you really want to restore from the selected snapshot. Click Continue to proceed.
The restore begins, and a process bar displays. When the restore is complete, your Mac reboots automatically.
[NB : You and others can do research to further document this knowledge of which I am not the author but a humble user.]