Freeing up memory - migrated photo library counting twice

[gcfalco]

I need to free up space to move my new-ish Pro 13 to Big Sur (good idea or not is another thread!). I've had a good house keep but am still 8GB short of the space required.
When I go to Storage it suggests I've got around 40GB of both photos and of documents. But I'd have expected my documents to less than 1GB.
When I go to Finder - Documents it shows I do have less than 1GB of docs as expected.
Going back to Storage, it appears the extra 39GB in Documents is the "migrated photo library". I'm unclear the point & purpose of this but it seems to pretty much duplicate the contents of Photos.
Okay, so why not delete the MPL? I tested this on one photo - deleting it from the MPL also deletes it from Photos, not an outcome I want. So it looks like the photos aren't duplicates, it's one set with two ways of filing them.
So getting to my Q: is the MPL being counted twice by Storage? There's only one set of photos but they're being counted in both Photos and Docs?
If that's the case how do I free up that 40GB?
Many thanks in advance for any (simple - I'm a beginner!) advice.

 

[MacInWin]

Welcome to the forum. It would appear that you have selected the option in Photos/Preferences NOT to check the "Copy Items to the Photos Library." That is why, when you delete the file, the image disappears from Photos. So, in that case, the images are NOT duplicated. If you had checked the box to Copy Items to the Photos Library, they would have been imported into the photos database and the various jpg/heic, whatever files could be deleted safely. Not that it would have saved any space, as the images still would be on the drive, but as you found out you should not mess with the file if you expect Photos, as you have it set, to still know where the image is.

About the only thing I can suggest at this point is to ensure that the trash has been emptied. You didn't mention what Mac you have, or how large the drive is, but to have insufficient space for an upgrade is pretty tight. The OS needs to have 10-15% of the drive free to operate efficiently.

One thing you might try is to move all of the files in the Migrated photo library to an external drive temporarily, do the upgrade, then move them all back to where they were before the upgrade and see if Photos can find them again. If that doesn't work, you'll have to re-import them to a new copy of photos database, but we can talk you through that after the upgrade.

 

[toMACsh]

I don't know if this will be beneficial to people reading this, but...
The topic says "freeing up memory" but the post is about freeing up space on the hard drive. That is not memory. Sometimes terminology used incorrectly can confuse the meaning, although not so much in this case. It's just a good idea to use terminology correctly all the time.

Anyway, MacInWin looked past the term and provided an excellent answer.

 

[MacInWin]

I've been accused of being pedantic when I point out the difference. Thanks for taking the heat for me!

 

[gcfalco]

Hi - thanks for the advice (and yes even as someone new to this forum I do understand memory vs storage but going through every small item on that laptop to save space has caused me to lose my marbles!).
It's 1 yr old MacBookPro 13 with 256GB storage. How it's so full is baffling but hey.
I could shift photos to the cloud but once had a bad experience trying to get them back so shifting them to another drive looks like next steps (though as an apple novice that makes me nervous too! Formatting the external drive, etc?).
Any further advice gratefully received.

 

[MacInWin]

macOS can write to a drive formatted with exFAT format, but not NTFS. Most drives come with NTFS (Windows preferred) format. Fixing it is easy. Open Disk Utility (Applications/Utility) and click on "Show" button and select Show All Devices. Now click on the external drive and then choose Partition. Pick GUID and either macOS Extended Journaled or exFAT or APFS for the format. Let it do the formatting. At the end the drive will be remounted and available for you. (This process will erase EVERYTHING on the drive, so if it has something you want to keep, you'll need to put those files somewhere else until the formatting is done.)

 

[toMACsh]

I've been accused of being pedantic when I point out the difference. Thanks for taking the heat for me!

I am pedantic, and proudly so. It is my sincere hope that military folk with access to the nuke button are as careful. (among others) Ok, so it's a bad analogy.

 

[MacInWin]

Military folk are VERY pedantic, to the point of obsessiveness. Mistakes when dealing with weapons can be quickly fatal.