launchd and kernel task are writing excessively to disk (and constantly running) on my mac. I'm running macOS Sierra version 10.12.15. Below are screenshots showing excessively logging. enter image description here

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I used clean my mac 3 to clean out like 30 gigs of systems logs, but they keep coming back. Here's a screenshot showing that a few hours after cleaning out the 30 gig system logs they are back at 6 gigs. Any idea of what's going on? Should I not have cleaned out system logs?

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1 Answer 1


Woah - your launchd is quite busy. Before you run any clean, I would save your work and do a shut down and then safe boot. The safe boot is when you hold the shift key after the startup chime sounds (or would sound if silenced).

This startup will take quite some time and it sets aside things link font cashes, all non critical kernel extensions / drivers / program start up.

Once the Mac is running - check on the activity monitor and grab screen shots to compare to yours above. After 5 minutes, you should have a very idle system. If not, disconnect from all networks and repeat the safe boot one time.

At that point, you’ll know if the core OS needs to be reinstalled if it’s not behaving in safe boot mode. If it does behave in safe boot, try a normal boot.

Next up if the normal boot fails - try making a new user and setting that user to log in at boot and restart.

Sorry this isn’t a “do this to fix” sort of answer, but you’ll need to triage a bit to get a feeling if this is software related and user/OS software related.

The log files themselves don’t cause issues - it’s the configuration or changes you brought to the standard install that’s logging all the messages. Imagine a leak in the basement - clearing the logs is hiring a contractor to come pump it out, rather than figuring out what’s leaking in the first place.

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    I ended up having to reinstall the OS. A lot more was hosed than I initially found. Thank you Mike! Commented Jul 18, 2017 at 23:45
  • Good call @AndrewCassidy - glad you didn’t spend too much more time before the install. I’ve never been a fan of any clean tool. You still need backup, so generally it’s best to get on with a reinstall than to try to hard to mend some types of os damage.
    – bmike
    Commented Jul 19, 2017 at 0:29

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