Mac not moving photos and videos to iCloud and freeing space on the local storage.

You also have the option of putting the Photos Library on an external drive. The drive would need to be formatted in either APFS format or Mac OS Extended (Journaled) format. The drive must be connected directly to the Mac by cable, not networked, clouded, NASed, etc. Additionally, the drive can not have had Time Machine on it since it was formatted. There have been so many problems with using incompatible drives that the newest macOSs won't even allow a Library on a non-Mac formatted drive to open, since there is a chance of damaging the Photos database. See this:

Move your Photos library to save space on your Mac   

Especially on a portable computer, the System Library should be kept on the internal drive, if you can.

I import my Old Family Pictures and my new Nikon pictures to Photos Libraries that are not the System Library. I edit, rate, and organize the pictures there, picking the best ones to transfer to my System Library of favorites. That Library can be small enough to remain on my internal drive. I also have several Libraries for archiving pictures. I and most experienced Photos folks, use the trusted 3rd party app PowerPhotos ($40) to handle multiple Libraries, copying stuff between Libraries while maintaining album and folder organization.

As the article on iCloud Photos says, you can't think of iCloud as a backup, because mistakes are backed up, too. So with iCloud, you can't go "back up" to an earlier date before the mistake. However, iCloud works as a limited off-site backup against a disaster that wipes out your local hard drive backups.

Photos Libraries can never be used from iCloud Drive, or even transferred there. However, if you make a dmg file of the Library (with Disk Utility,) or if you remove the ".photoslibrary" extension from the Library package, then that can be stored in iCloud.

17 GB is indistinguishable from 0. You've got to get rid of stuff, and that's hard with no storage to work with. Optimize may not be working with no room to manipulate the files. What is your storage on this Mac? At System Settings>General> Storage, my Mac says 745 GB of 1TBB used. What does yours say?

You certainly need a couple of external drives.

Are you using iCloud Drive?

I would do these two things:

• Restart the computer (of course)
• Re-start in Safe Mode. This bypasses certain potentially disruptive processes, and it often helps. Safe Mode is different for different computers, so see this: 

           Start up your Mac in safe mode - Apple Support 

Safe Mode may help. But if things work better in Safe Mode but then are bad again when you go back to normal, then your problems may stem from interfering or from apps auto-loading junk.

Do you use a VPN or "Cleaner" apps or "Virus catcher" apps? These are holdovers form Windows thinking, and they do only bad stuff on Macs.

Do you have Windows stuff like One Drive, etc on the system? Some of that may count as "System Data."

My "System Data" has been varying between 800 MB and 8 GB.

This is an article from Apple Support that discusses reducing storage.

Free up storage space on Mac - Apple Support

It's really pretty obvious stuff.

Here is an article that I find too long to read, but it has lots of information:

How to free up ‘System Data’ and other st… - Apple Community

though it may not help, much.

I Gemini'ed "The storage used by "System Data" on my Mac is getting bloated. How do I recover space on my local storage?".

It gave me the following:

Restart the Mac, Empty trash

Purge Local Time Machine Snapshots <--- This worked and cleared out a lot of space

Clear Out Massive App Caches

Delete Old iPhone/iPad Backups

Only deleting the local Time Machine snapshots helped.

I now have 145 GB free on a 512 GB internal storage. Photos is taking 6.76 GB with iCloud options enabled.

I don't have any Windows carryover habits besides Mac versions of Microsoft Office.

I tried the steps here: https://www.google.com/search?q=The+storage+used+by+%22System+Data%22+on+my+Mac+is+getting+bloated.++How+do+I+recover+space+on+my+local+storage%3F&client=safari&hs=M8DW&sca_esv=aafa6ca6a126c165&rls=en&sxsrf=APpeQnuQtOVznouJRvRMx7yjS1aV1CPfdg%3A1793141584681&udm=50&fbs=ABfTbFVyMZGZf1hfvX9uKjN_-G8cxpBkeIeqYwoCbfNVc4vKE0nzDtz46ks8VcXZ-FAj7roWouGYoa-8wJKyeh_fRvLGHeHEmoge7jS-g4vwk2kja_ztPuJ4onrO1XzH0PmFbzSNYPiRbNm8uw1a5chAJe1Xkx1IE_Xi9IjKXNkYgUULpmN1-880B_5nzUlrgB1Pj-_jS3uXdywNoRZJdLBad9w6GbYVRg&vsint=&aep=1&ntc=1&cs=0&sa=X&ved=2ahUKEwjY9b75pNuXAxUqMlkFHafvO5oQ2J8OegQIEhAD&biw=2454&bih=1249&dpr=1.5&mstk=AUtExfCesMUdeAJdUYFHtqHWsV6ROiEhx58Tz_0KFfsB4dpsbW1JuBtzD2m8kUTASwHypH3s_QDED7QDKScHnjssfBwN64rvNqn0M__Ekepw1qBTSn_Dm4b0OWwTCd1QAgWAbQrI22Q26PeQYdfi_4zf-4DKzlILP9I5hIkhqQn74TyHN8xpu5cqZ1Hc5CmX2hQ2if26-pouCih3IsJRKC4UX7G8SGoA1mbC3q_-OJi3a7p1TXKAyfbiqHZa29E08-ji75RQxInYXErG9HkRDIEGICqjiv8j8MpFxM1beJnpdV3bsdPHQIflo95osEZOTc4HO80mbXTx_QJG4Q&csuir=1&mtid=Uivhap20CtTe5NoPlNmvgQU

Sorry for the ungainly URL.

Optimization happens on the background should low space necessitate keeping optimized versions on your Mac. If you’re uploading a substantial number of files, you may want to do that in batches to allow optimization to work.

Aloke wrote: … "when the local storage was totally depleted."

Many operations use the iPhone's empty storage space to move files around. If you run out of storage, then those operations may not be able to be completed and, ironically, that can mean that even deleting doesn't work. If you have less than 10% available, then things can get lost forever. This is also true if your iCloud storage space gets low. Until your local storage is reduced below 90%, you'll have slow-downs and other troubles.

On my 1 TB MacAir I found crazy things happening when I had less than 150 GB free, so I try not to use more than 85% of my storage.

Photos Optimization is entirely automatic, and you have no control over it. I doubt that Disk Utility is especially reliable for this.

External drives are essential not just for backups, but also to move stuff so your internal drive can be worry free. For a MacAir, it's particularly awkward to keep a Photos Library on an external drive. I use external drives to keep other files so that I can keep my System Library on the internal drive. But you don't have to keep all your pictures in the System Library. You can have separate Libraries, like archives, that you don't need to access very often on external drives.

You can see this:

Understanding iCloud Photos - Apple Community

You may also want to see this:

Basic Concepts and Terms About Photos - Apple Community

That's great! You have over 25% free storage to work with. Don't get below 15% free!

Using Optimized Storage makes you vulnerable to losing data. You need backups on an external drive, and with optimized storage your stuff isn't on your Mac available for backup. See this:

Backup iCloud Photos from an Optimized Mac - Apple Community

As to Time Machine backups-- those can be pretty important. The local TM snapshots only hang around for a day or two before they're replaced by new ones.

You need an external drive with a volume dedicated to Time Machine. I have a small 1 ounce drive that I carry around with me and plug in to my MacBook at least once a day. Unfortunately, in the last 6 months portable drives have at least doubled in price. But without an external drive, and with only ½TB of internal storage, you're going to be spending an inordinate amount of time worrying about storage, constantly going through your files trying to find ways to free up space. I speak from experience.

Your link doesn't take me any place.

Thx.

Any way to monitor the progress of that process? I don't see the "free space" on my local storage increasing (using the Disk Utility app).

I was hasty in importing the media and got a bad scare when the local storage was totally depleted. I would like some reassurance that the process is working and won't get back to that condition.

How do I verify that the system is working as it should?

Thank you for the reply. I am new to MacOS and it is a steep learning curve after using Windows for 30 years. But we won't go there.

I have stopped importing media into the MacBook's Photos app until the local storage usage is figured out. "iCloud Photos" and "Optimize Mac Storage" are enabled.

The Mac's Settings-Storage shows only 6.7 GB used by Photos. However, "System Data" has grown to 276 GB in that process , reducing available storage to just 17 GB 😮

Even moving the photo library to external storage won't help. And the Mac seems to be in no hurry to recover storage from "System Data".

What should I do? I expect the apps to start complaining with so little storage available.

Worried,

Aloke

Thank you for staying with me on this.

I have backups galore of my photos and videos: on a NAS, on Google Drive, and Dropbox. I have 5 TB tier on Google Drive and Dropbox, and was thinking of cancelling Dropbox and paying for more than current 2 TB on iCloud, now that I am have switched lock stock and barrel to Macs.

Thus, I was in the process of importing tons of photos and videos into the Photos app (Mac), syncing with iCloud, and having it on all my iOS devices. That got interrupted by running out of local storage when I imported huge 4K wedding videos and stills. For some reason, the Mac wasn't managing storage optimally, even though I had "Optimize storage" enabled.

The destination of Time Machine backups is an external WD drive and my NAS.

I am going to take it slow and import some media at a time now, giving the Mac enough time to upload the files to iCloud. I have a symmetric 5 GB/s fiber connection .. so I really should not need to do that 🤷🏽‍♂️.

Aloke

Is using the Disk Utility the best way of verifying that the Mac is indeed moving the files to iCloud Photo and freeing up the local storage (as it is supposed to do)?