Today’s Question: You indicated that you keep the Lightroom Classic catalog on the internal hard drive and a backup copy on your photos drive. Doesn’t Lightroom get confused about what catalog to use when you plug in the photos drive to the main computer? Or am I misunderstanding this process?
Tim’s Quick Answer: Lightroom Classic does not get confused about the backup catalogs on my photos drive, because Lightroom is always opening my master catalog upon launch. This can be managed by either specifying a particular catalog you want Lightroom Classic to always use, or to have Lightroom open the most recently used catalog every time Lightroom is launched.
More Detail: I do indeed keep my Lightroom Classic catalog on the internal hard drive of my computer, and I store backup copies on the same external hard drive that contains my photos, in part so that when I backup my photos drive I’ll also be making an additional backup copy of my Lightroom catalog backups.
Lightroom doesn’t get confused about the backup copies of the catalog, in part because Lightroom isn’t really looking for those backup copies.
By default, when you launch Lightroom it will open the catalog you were using the last time you launched Lightroom. For most photographers (especially those using my advice to only use a single master catalog) this works great. Every time you launch Lightroom, you simply want to use the only master catalog you have.
Taking this a step further, you can also specify a particular catalog that you always want Lightroom to default to, which is helpful if you sometimes need to work with a temporary “test” catalog, for example. In the Preferences dialog in Lightroom Classic you’ll find the Default Catalog option on the General tab. Click the popup, and select the recently opened catalog that you want to always open when you launch Lightroom.
But again, the presence of backup copies of your catalog won’t confuse Lightroom, provided you don’t ever actually open a backup copy of your catalog in Lightroom. If you keep the backup copies as separate backups that you don’t open, Lightroom won’t be confused.