Just to follow-up, I never found a solution to this problem, though I appreciate the help that various people offered.
In addition to the suggestions in my original message below, I also tried the following: 1. I turned off Power Nap, but that did not help. 2. I disconnected the USB cable that allows my UPS to communicate with my Mac, but that did not help. 3. I checked the links that David Schwartz mentioned -- they addressed why I'm having problems but not how to fix them. If anyone has any other suggestions, please let me know. Thanks again, Gregg -----Original Message----- From: "Dinse, Gregg (NIH/NIEHS) [C]" <di...@niehs.nih.gov> Date: Sunday, July 30, 2017 at 4:40 PM To: "'macosx-talk@omnigroup.com'" <macosx-talk@omnigroup.com> Cc: "Dinse, Gregg (NIH/NIEHS) [C]" <di...@niehs.nih.gov> Subject: Time Machine stops backing up Hi, About 2 weeks ago, I upgraded from Yosemite (10.10.5) to Sierra (10.12.6). I believe that this is when my trouble started. Until recently, whenever I looked at the Time Machine panel in Preferences.app, it would show times for the latest backup and the next backup that were roughly an hour apart, as expected. Now when I look, it has often been several hour (maybe even 12 or more) since the last backup. If I tell it to backup now, it backs up. However, an hour from then, the next backup time often jumps by an hour but the latest backup time stays the same. In some cases, I think it performs a backup eventually, but certainly not every hour. I don't recall if it has gone for days without a backup, but I think it has. Does anyone know how to fix this? My disk has plenty of space left. I have tried several suggestions that I found online, but so far none have helped. I unchecked and then rechecked the Back Up Automatically button. I deselected and then reselected the drive used for Time Machine backups. I rebooted many times. I ran the following command from Terminal: sudo defaults write /Library/Preferences/com.apple.TimeMachine RequiresACPower 0 Supposedly all of these "fixes" have helped some people with this problem, but they have not worked for me. In case something was corrupt in the 10.12.6 combo update, I ran that again. Things seemed to work for a few days, so I thought that fixed it, but now the problem is back again. Does anyone have any other suggestions? Thanks, Gregg _______________________________________________ MacOSX-talk mailing list MacOSX-talk@omnigroup.com http://www.omnigroup.com/mailman/listinfo/macosx-talk
