Lightroom Classic Storage

I have images scattered across a couple of internal hard drives, some external hard drives, and I'm experimenting with adding images on Google Drive which is a cloud service that my computer treats as a local drive. I'm using Windows 10. Lightroom Classic is handling images very well on all of these different sources.

I have several external hard drives that everything is stored on.

My images are on an external enclosure that has four drive bays, because they can’t all fit on MacBook Pro internal storage. And, because it is very important to keep at lot of unused space available on the system volume. When I sit down at my desk with my MacBook Pro, I plug that in so that Lightroom Classic can connect to all the images. I keep the Lightroom Classic catalog on the MacBook Pro.

Lightroom Classic has no problem importing to and cataloging images on multiple volumes. Each volume is listed at the top of the Folders panel, so you can expand it and see all the folders that have been cataloged on each volume.

If there is a set of photos I would like to edit while away from the desk, I have Lightroom Classic generate Smart Previews of them. Those are stored in the same folder as the catalog on my MacBook Pro. When I return to the desk and connect to the hard drive full of photos, the edits applied to the Smart Previews now apply to their originals.

A storage volume connected with USB 3 is fast enough for storing originals cataloged by Lightroom Classic. The real need for fast storage is the volume containing the preview cache (same folder as the catalog) and the Camera Raw cache (set in Lightroom Classic preferences) because those are the files that are read and written while you edit in the Develop module. For that reason I keep those on the very fast internal storage of the MacBook Pro.

As @dj_paige  wrote there's no right and wrong here. You can stored your RAWs whereever you want.

The only thing to keep in mind is the performance. As a rule, access to RAW files on internal hard disks is more efficient than access to external disks or via the network. But that also depends on the connection type of your external drives (USB, USB 3 etc.) 

When you use Lightroom Classic, your RAW files can be stored anywhere on local hard disks (internal or external), or on a network drive. There is no right or wrong here, wherever you want them to be stored will work with Lightroom Classic.