2 questions:1) plz clarify disk storage indicators, and 2: how to purge “purgeable” space

[VitoJr]

Please enlighten me:

Moved a 1.25 go file from my iMac M3 hard drive to free up disk space. Get Info is showing the 125 Gb as purgeable but still included in the total storage; Disk Utility is showing the 1.25 go as being used (as if I did not remove the file; and About this Mac/More Info clearly shows the 1.25 Gb as being freed.

question 1- why are these 3 routines not consistent in the storage availability, which one do you use as being the most accurate?

question 2- how does one “purge” the 1.25 go as noted in Get Info.

Thanks

Vito

 

[MacCheetah3]

Purgeable Storage Space on Mac: What it is & How to Free It

You may find a “Purgeable” storage space when looking at disk storage and disk usage in modern versions of macOS, including Big Sur, Catalina, Mojave, Sierra, etc, either within the Abo…

osxdaily.com

question 1- why are these 3 routines not consistent in the storage availability

On my Mac, Disk Utility’s “Available” plus the “Purgeable” in Get Info add up to the “Available” in the About section of the Settings app.

question 2- how does one “purge” the 1.25 go as noted in Get Info.

Purgeable Storage Space on Mac: What it is & How to Free It

You may find a “Purgeable” storage space when looking at disk storage and disk usage in modern versions of macOS, including Big Sur, Catalina, Mojave, Sierra, etc, either within the Abo…

osxdaily.com

which one do you use as being the most accurate?

Answering that involves some gray area. Because purgeable is quickly available if needed it can be considered free space. Think back to the days of HDDs, in which the OS removes the markers for the data when you ‘trash’ files/folders but doesn’t erase the data from the physical drive — just eventually overwrites. The gray area pertains to how SSDs function. At the moment, System Settings is reporting ~136GB available because it has calculated about ~108GB is purgeable. However, Disk Utility reports 28GB available, which is what’s available on the NAND chips (to put it simply). This 28GB vs. 136GB of free space to work with can be significant when it comes to SSD management, namely garbage collection and wear leveling. And, therefore, I am a little concerned about only having ~5% free space on the SSD — again, from an operational, technical standpoint. With that said, the NAND has less than 19TB written in total and the SSD controller is estimating 99% remaining drive health (as reported by DriveDX). So, such a small available storage space isn't detrimental, at least in average/common use(?)

 

[Arctic Moose]

Also, in many cases macOS/APFS will not store copies of identical files more than once. This means that if you move or trash a 1.25 Gb file you will not recover any space if there is a copy of that file still on the disk.

 

[MacCheetah3]

Please enlighten me:

Moved a 1.25 go file from my iMac M3 hard drive to free up disk space. Get Info is showing the 125 Gb as purgeable but still included in the total storage; Disk Utility is showing the 1.25 go as being used (as if I did not remove the file

Also, in many cases macOS/APFS will not store copies of identical files more than once. This means that if you move or trash a 1.25 Gb file you will not recover any space if there is a copy of that file still on the disk.

Ah, yes, I did forget about copy-on-write:

 

[VitoJr]

Thanks very much for your speedy responses and comprehensiveness of your answers.