Thanks for that information, I didn't know it was an option to have multiple storage devices associated together, and I hope it works for you as you described. My post was erroneous regarding AFS eliminating the volume concept. That was due to a misunderstanding of an article I read, and only seeing the physical disk in Disk Utility since High Sierra by default does not show the volume until you click on View and select Show All Devices. I believe the local snapshots on my laptop were eliminated when I turned off automatic backups, which is good because I read that it is a bad idea to manually delete them from /.Mobile Backups where they are apparently stored and that doing so can cause Time Machine to stop working. In the end I decided to stop using Time Machine altogether and removed the Time Capsule as a Time Machine backup device, with the hope that this has resulted in the elimination of all the storage used on my laptop for Time Machine. I decided to leave the backups already on the Time Capsule there in case I need them someday. I have now switched to Carbon Copy Cloner and am using the G-Technology G-DRIVE with it and am very pleased with its fast performance and greater flexibility. I find Time Machine frustrating due to the lack of ability to control exactly what it is doing, and exactly how much storage it uses, especially on my MacBook Pro. I think turning off local snapshots and automatic backups probably solves the problem in terms of storage on my MacBook Pro, but I found it difficult to find definitive information on exactly how to wrangle Time Machine into doing precisely what I want it to do. I realize it was designed to be easy to use for those who don't want to exercise precise control with the added complexity that brings, so it does provide a set-and-forget tool for people who just want to turn something on and not have to deal with it again, but I am the type of user who wants extremely precise control over what my backup solution does. Carbon Copy Cloner, with its extensive documentation, provides that for me to my satisfaction. I am not claiming that someone with much greater knowledge of, and experience with, macOS than I have cannot control Time Machine to their satisfaction, so part of my frustration may just be due to lack of knowledge and experience.