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Old 03-03-2019, 11:13 AM
jkbull jkbull is offline
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Join Date: Sep 2009
Posts: 6
Lightbulb Workaround for 100% CPU usage by sdbackupbytime

First, I want to mention that I've used SuperDuper! for years and consider it a great product. I'm currently using SuperDuper! 3.2.4 (v 118) on macOS High Sierra.

This morning I awoke to find SuperDuper!'s sdbackupbytime process using 100% of CPU time. After quitting the process via Activity Monitor or restarting the computer, the process restarts and resumes using 100% of the CPU. (Well, 100% of one core, anyway.)

This appears to be due to a bug in SuperDuper! when a backup is scheduled to start during the hour after the switch to Daylight Savings Time. In my case, I had a backup scheduled to start at 2:00 am on Sunday March 10, which is the exact time that the DST switch occurs. (Interestingly, although the scheduled time was 2:00 am, the time in the description of the backup was "Every Sunday at 3:00 amů". That sort of makes sense because 2:00 am doesn't really exist; DST causes the time to skip from 1:59:59 to 3:00:00.)

The workaround is to change the schedule so the backup starts before 2:00 am or after 3:00 am. Then all is well. Setting it to start at 2:00 am, 2:05 am, or 2:55 am triggers the problem.
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