Backing up optimized Photos library from iCloud

I have a huge Photos library (400GB+) that I have backed up to iCloud. I chose to optimize the library so that it would continue to fit on MacBook Air's hard drive. However, it's making me nervous to have all my originals in the cloud though with no non-cloud backup. However, I do not have enough hard drive space to download my originals to my mac. I want to duplicate my Photos library to my external drive. What is the best way to do this? Should I create a new empty Photos library on the external drive and then let iCloud import all the photos to it? If I just paste my current optimized library to the new drive I get a weird message about deleting photos which freaks me out. What's the best way to do this?

A warm welcome to our Mac-Forums.

If what you are after is a duplicate of your Photos library, this is easily achievable.

You will need an External Hard Drive (EHD) formatted Mac OS X Extened Journaled.

Your Photos library should be found at Mac HD > users > your name > Pictures > photos.photolibrary (I am doing this from memory. The path is correct but the exact wording of the library I am guessing at).

Having located the Photos Library, copy it to your EHD. Obviously, this will be a copy of the library as it is now, but you can replace this with further copies at regular intervals according to how much new stuff you add.

I would hope that, in addition, you regularly backup your Mac via Time Machine and via cloning software such as Carbon Copy Cloner or SuperDuper! These will need separate EHDs.

Time Machine will ensure that everything on your Mac including your photos are always up to date and the cloning backup can be done weekly or otherwise to suit your needs - and is bootable-a huge advantage.

Please post back with any queries.

Ian

The issue is that it is an optimized photoslibrary. I.e. The originals are on iCloud and only the optimized (thumbnails) are stored on my computer to save space. Does anyone have experience transferring this type of library to an external drive? When I tried to do what you suggested I get a message about deleting photos and syncing with iCloud. I don't want my 400gb of photos to get duplicated or deleted in iCloud.

What Ian is suggesting is that you copy your Photos library from iCloud to an external hard drive before taking any further action. Also, you're a brave soul storing over 400GB of photos or anything else to iCloud. Personally, something I would never recommend doing.