For posterity - Apple centric setup and photos library for 4TB of images and video

A Photos Library cannot be stored on a network share, only on the internal drive or an external drive with a wired connection, so a NAS is out. This is described here: Move your Photos library to save space on your Mac - Apple Support

4TB is currently the largest amount of cloud storage you can subscribe to. But it would not be feasible to keep a 4TB Photos Library with just to 4TB of Cloud storage.

And you would have to be very patient with such a large Photos library. The Photos.app is using very ambitious and advanced artificial intelligence algorithms to make browsing and searching the library easier. After each system update that is changing the algorithms, Photos will scan the library again to recognise the scenes, objects, faces. These processes are computationally complex and need a lot of processing time. For example, scanning my library with just 55000 photos and videos took two weeks to complete. For a much larger library the scanning might never finish between successive system updates. Also the uploading to iCloud and the syncing with iCloud would only be feasible for a smaller library.

In your case I would recommend to create a small library to keep in iCloud Photos and sync to all your devices, and keep an archive of all your photos stored locally on external volumes.

That is what I have done - a smaller library in iCloud with only my favourite photos that I want to be able to access on all devices, small enough that my device with the least internal storage can sync with iCloud Photos without running out of storage.

And several larger libraries on external drives as an archive of all photos.

iCloud Photos is primarily a syncing service to keep your Photos Library identical and in sync on all devices. So your device with the least storage will be the bottle neck how much you can store in iCloud without overtaxing the smallest device. All photos and videos you are keeping in iCloud will be downloaded to all your devices syncing with iCloud Photos, at least as a smaller, optimized version, which will need roughly 10% of the storage used in iCloud. So at best, 4TB of iCloud Photos Library will result in a 400GB Photos Library on your iPhone.

1Sia1Som wrote:

Thanks so much for the responses.

Just so I'm clear:

1)If I kept it all on external drives and had enough memory on my smallest device - could it sync everything?

2) Does the iCloud storage limit actually matter bc I thought photos didn't count towards that?

1. Theoretically, yes. But it would be slow as molasses for a library with 2 TB, even with Apple's latest hardware.
2. Yes, iCloud Storage will matter. iCloud Photos Library uses your iCloud+ subscription storage plan. Only My Photo Stream and shared albums are free, but there are limits, because they are free: iCloud: My Photo Stream and iCloud Photo Sharing limits

The max iCloud storage space is 2TB, unless you also subscribe to the largest Apple One subscription too when you can then hit 4TB. So, iCloud may not be a solution. Or, it may if you have multiple libraries that you keep (eg. family, drone, fun stuff, etc.)

I have my library on an external drive, backed up to another one. Then, also burn to m-disc archival storage each year all the newer items. And, have copies with family just for posterity.

I do not think that you will get any Cloud service that will take that amount of data in any kind of user friendly way.

But there are possibilities in the Cloud: for instance, create a personal account on YouTobe or Vimeo for your videos. They can be marked private. That's a good back up. Photo services like Flickr will take all your images and probably most of your videos too, and the advantage is that they are accessible from any computer with the password you create.

But if you want to maintain an editable library then your library will reside on your Macs and external disk. Lightroom Classic will work with the masters stored on a NAS, but the library needs to reside on the Mac disk or attached external.

Lastly, check out Mylio. I know of someone who has at least 1,000,000 images in it. It's excellent for sharing across devices, and is very user friendly.

> apple centric setup and photoslibrary

I have a similar plan but I try to keep images and movies as much platform agnostic as I can.

Image (.jpg, .heic, .png, .tif) metadata is quite well standardized so I routinely insert dates, locations, captions, keywords and ratings to them so it travels with them (IPTC and XMP synced because currently some app prefers the other).

But movie metadata is still a mess and a moving target so I routinely insert only date and location metadata to them and keep most of the captions and other metadata in a separate spreadsheet and insert it to movies if there is a solid standard for that.

https://exiftool.org/forum/index.php?topic=14308.msg77101#msg77101

Movie codecs is another matter. A few years ago I converted old movies to current H.264/H.265 and AAC .mp4 movies (and of course archived also the originals...).

I currently archive images and movies as plain Finder folders on a master Mac OS Extended GUID HDD which I clone to two identical HDDs with Carbon Copy Cloner. Those old 3TB Seagate HDDs are way slower than new SSDs but I still have my main "cold" archives on them because I have heard that SSD might not be so reliable in "cold" powerless storage.

I use Photos library only as a viewer and a means to sync it to iOS devices. I do not believe that a current Photos library database is readily readable after 50 years or so.