How to prevent dictionaries from being deleted when space runs low?

Owl-53 wrote:

AFAIK - there is no such thing as a " Purge Mode "

Nor are there any dictionaries at /Library/Dictionaries or ~/Library/Dictionaries

The answer is more simple. Keep at least 100 GB of free storage. Pay close attention to what the operating system is telling you. If it says "available" storage, then that's simply a fantasy. Look for the word "free". You can find it in Disk Utility.

100 GB is a good working buffer to have. At around 60 GB free storage, you'll start to experience performance degradation as the computer struggles to delete the "available" storage that it used to tell you about. This may include your dictionaries. Anything less than 60 GB risks catastrophic system failure. That's the range where the operating system's own virtual memory system can consume all of your available storage in an instant.

Even with those guidelines, you can still get into trouble if you use Xcode or beta software.

Reboot more often. It helps to prevent some data loss from items that were in only stored in a cache buffer & never fully transferred to the drive. Plus rebooting once in a while can allow the system to recover some of the storage space when macOS & your apps are restarted. macOS & some apps tend to hang onto things excessively & will only let go of them after being restarted.

And never let the Free storage space drop below 20GB since that 20GB can disappear very quickly when you are doing very little with the system...most workloads require much more Free storage than 20GB like @etresoft mentioned. Bad things happen when a macOS volume runs out of Free storage space. If you are running low on storage space on your boot drive, then you may need to relocate some of those files to an external drive, or consider purchasing another computer with more internal storage

Catholic OS wrote:

Is there a way to prevent MacOS from deleting dictionaries associated with the Dicionary app when space on the computer runs low? It is an unbelievably annoying bug that often completely disrupts my workflow. Why can't the OS simply notify me that the space is running low and recommend the deletion of certain files rather than making the very Apple-like decision of what I need and what I don't?

As for a warning when the computer is running out of space ?

There is usually present of Visual Warning that goes something like this . . . .

1 - " The Computer is running Low on Space "

2 - " The computer has run Out of Space "

In either instance, this usually means exactly what it has said

Do not bother looking at System Setting >> General >> Storage

This is only Eye Candy that does not give a proper accounting of Used versus Free Space

Use Disk Utilities

There remains yet another option, which is not always welcome for some

Quick Fix Actions:

 For Apple Silicon computers, use Disk Utility to erase a Mac.

For Apple Intel computers, use Disk Utility to erase an Intel-based Mac, then reinstall macOS.

Always make a Time Machine backup before proceeding.

Migrate only the user account, not the entire system.

Reinstall only the necessary applications from the Apple App Store or directly from the developers.