Safe to delete? Multiple Photos libraries and old iPhoto library

[Arthur]

I would like to delete excess files on my wife’s 2009 27" iMac so that the original 1TB HDD can be replaced with a 500 GB SSD. "About This Mac > “Storage” reports “560 GB available of 999 GB” on the original HDD. It would be desirable delete unneeded files so that at least 100 to 150 GB of free space remains on the new SSD after the change-over. The late 2009 iMac runs under macOS 10.13.6 High Sierra, backed up to external drives by Time Machine hourly and Carbon Copy Cloner weekly.

Currently there are 3 Photos libraries and 2 old iPhoto libraries in the Pictures folder. See screenshot of the Pictures folder as displayed in Finder below. Which of these are safe to delete so that no image files are lost? If I recall correctly, the old iPhoto library was migrated to the Photos app years ago. That may account for the filetype “migratedphotolibrary” indicated for iPhotolibrary 2.

Question 1: Is it safe to delete the two old iPhoto Library files? Indicated file sizes are 94.72 GB and 623 KB. When launching the old iPhotos app, the message appears: “Your photos have been migrated to Photos. …”
Question 2: What is the best way to delete the iPhoto app? Simply drag iPhoto.app to the trash bin, or use an app such as Appcleaner to delete the application and its supporting files?

Photos Library files:
There are three Photos Libraries. Photos Library 2 is the only one in use. I assume that multiple libraries exist because several years ago (probably 2015) I experimented with the Photos app, or there may have been some confusion about setting up the 2009 iMac for my wife’s use in early 2015 after purchasing a new Retina iMac for my use.

The Photos Library 2 (file size 146.69 GB) contains digital camera-acquired photos from January 2002 to today (8/23/2020). As seen in the screenshot of the “package contents” in Finder below, the folders in the “Masters” sub-folder date back to 01/2002.

Similarly examining the “package contents” of Photos Library 3 (not in current use), the earliest folder in the “Masters” sub-folder is 01/2002 and the latest is 06/2015. My interpretation of this is that Photos Library 2 and Photos Library 3 contain the same photos up to 06/2015, but only Photos Library 2 contains photos beyond that date.

Question 3: is it safe to delete the Photos Library 3 file?

This library appears to be redundant. As far as I can tell by spot-checking the library “package” files as described above there are no images in this library that are not in Photos Library 2. I have not attempted to launch the Photos app (using the option key) to access the Photos Library 3. iCloud Photos is enabled for my wife’s iMac, iPhone and iPad Pro, and I do not want to cause any problem by accessing another photo library.

[geoffaire]

I’m very risk averse when it comes to photos. Is it worth backing the photos libraries up to an online resource and/or a removable hard drive before deleting. I’m sure you could get a 256GB USB Memory stick for a relatively small amount just in case.

[Timo]

I agree with @geoffaire, both with regard to backing up all the libraries and having multiple copies of these back ups. Only thereafter would I act on inferences like “this library appears to be redundant.”

[jec0047]

As far as iPhoto goes, take a look at this thread. Pay particular attention to the advice given by @bowline and @tomalmy, and ignore the advice given by one @jec0047.

For your (possibly) redundant Photos libraries, I share the previous paranoias expressed by @geoffaire and @timo. Delete them if you must, but make sure you have viable archives.

[Arthur]

@jec0047

As far as iPhoto goes, take a look at this thread . Pay particular attention to the advice given by @bowline and @tomalmy, and ignore the advice given by one @jec0047.

For your (possibly) redundant Photos libraries, I share the previous paranoias expressed by @geoffaire and @timo. Delete them if you must, but make sure you have viable archives.

@jec0047, @Timo, @geoffaire - thank you for the replies.

Some followup for you:

After backing up and then deleting the old migrated iPhoto libraries and the redundant Photos libraries, emptying the Trash folder and re-booting, I was pleasantly surprised to see that almost 190 GB of storage was recovered. "About This Mac > “Storage” now reports 756 GB available. “Get info” for the iMac HDD now indicates 249 GB used, compared to 560 GB available and 440 GB used before.

Others in this forum, including the referenced thread above (Photos and iPhoto), state that old iPhoto libraries and extra Photos libraries simply contain links rather than actual image files. Deleting these should not really recover substantial disk space, but that was not my experience. The reported disk space used changed from 440 GB to 249 GB.

I suspect that there may be some ambiguity in the way that Finder’s “Get info” and  "About This Mac > “Storage” report disk space used. Could it be that the actual files and the linked files are reported twice, indicating more disk space reported as used than is actually used?

Knowing the actual disk space used is important for my situation. I would be more comfortable with 249 GB used on a 500 GB SSD rather than 440 used on a 500 GB SSD.