Time Machine is a great, baseline, no-fuss archiving solution for macOS. While it has many drawbacks and can be fussy, it’s far better than not having a backup and it works generally well for the vast majority of Mac owners. It’s a great solution for family members who otherwise don’t back up. (Especially coupled with convincing them to subscribe to or giving them Backblaze or another highly related secure, automated, hosted backup service.)
If you’re frustrated with Time Machine’s limitations, however, you have other options. Econ Technologies’ ChronoSync always sits at the top of my list. It’s not per se backup software. Rather, it’s an exhaustive solution for synchronizing files between two local, two remote, or one local and remote location. Backup and archiving is just one of its many features.
With ChronoSync, you can select any drive, folder, or set of items on the source side and then choose to create an up-to-date copy, a complete clone of a drive, or an archive that retains older versions for access on demand. ChronoSync also offers flexibility in how you choose to schedule when operations occur.
For instance, one reader has two external drives in addition to their main internal drive on a Mac, and wants to back up the internal drive and one of the external drives to one backup volume, and the other external drive to a separate backup volume.
This isn’t possible with Time Machine, even though it lets you specify source volumes, exclusions, and backup destinations, and rotate through backup drives by removing and attaching them. Time Machine treats every backup destination as a place to backup the entire contents of selected drives.

Don’t let ChronoSync’s complexity daunt you. It’s all in the interests of configuration and control (and read the manual).
That’s not a limitation for ChronoSync, with which you can create any number of sync operations on a schedule among any sets of folders and drives.
While it may seem expensive at $50—especially as compared to free for Time Machine—it’s a perpetual license that includes all future updates. I do recommend reading the manual and viewing online tutorials to master settings. The program is well constructed, but has so many options that a seat-of-the-pants approach may not meet your needs.
This Mac 911 article is in response to a question submitted by Macworld reader Morgan.
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