HOW TO MAKE TIME MACHINE BACK UP TWO VOLUMES HOURLY
Some people want a belt and suspenders on their backup: two Time Machine volumes that are both kept up to date in the worst case of failure. Apple lets you attach multiple volumes to your Mac directly or over a network to act as Time Machine destinations. But macOS alternates each hour among attached volumes. Is there a way to have macOS back up hourly to both without manually clicking the Time Machine system menu and choosing Back Up Now?
Not precisely. You can try one of two alternatives:
Use , a free utility (donation requested) that lets you control certain aspects of Time Machine backups. You could change the frequency to every 30 minutes, so neither backup would be more than about 30 minutes old at any given time.
