External drives · Checking your drive
What is the Split Storage job in Background Activity?
Short answer: A background job that finds parts of apps' files that could live on your fast drive, keeps track of the ones that already do, and clears leftover installer downloads. Its checks report any problems as one notice in Background Activity.
Split Storage is the background job that looks at which parts of an app's files could live on your fast drive instead of your Mac, keeps track of the parts that already do, and clears out leftover installer downloads. It works quietly in the background and when your fast drive connects.
It's also where the checks on those moved parts report: if something is missing, orphaned or unexpectedly changed, you'll see a single notice on the Split Storage card in Background Activity explaining what happened and what to do.