82 Macworld • December 2019FEATURE
How to use iCloud to help manage Photos
libraries too large for an internal Mac drive
I’ve previously written that there aren’t any methods
supported by Apple that let you have a Photos
library at full resolution on a Mac if the library can’t
fit on your internal drive with the spare room you
need – or exceeds the drive entirely. Macworld
reader Matt wrote in with a workaround that offers
an approach much closer to what other readers
were looking for: one copy of a Photos library set
up with iCloud Photos that’s only thumbnails and
stored on your internal drive, and a second iCloud
Photos-linked copy that’s linked to an external drive.
His idea relies on how macOS lets you create
multiple accounts, each of which can be uniquely
linked to an iCloud account. However, it’s also
possible for two accounts or more to both link to the
same iCloud account. Normally, you wouldn’t want
this, because it would mean syncing the same data
in two places on your startup drive. But with the
way in which iCloud Photos and Photos for macOS
works, it’s a nifty solution.
Here’s the schematic of how to make this work:1.Attach an external drive with sufficient storage for
your full iCloud Photos library at full resolution.
(You can find this number at iCloud.com: log in,
click the Settings icon, and hover over the Photos
andVideossectionoftheStorageusagebar.)
2.Next, create a second macOS account called, for
instance, yourname plus photos, via the Users &
Groups preference pane.