kernel_task writes huge amounts of data to disk (> 1TB) - how to diagnose?

My MacBook (2016 with TouchBar) running macOS 10.13 has a 512GB SSD. Looking at the activity monitor after a couple of weeks of uptime (most of it spent in standby), kernel_task shows 1.43TB (!) of bytes written to disk right now:

Screenshot of activity monitor

What is wrong here - how can I diagnose why kernel_task is writing so much data to the disk? (This happens all the time after each reboot).

Memory pressure is still "green" most of the time. Running out of space is also not an issue so most of the data seems to be "temporary".

However, I am a bit worried about my SSD - writing 25 TB per year (in addition to the "regular" workload) does not seem to be a good idea...

Any ideas?


I had the same issue on my 2010 MacBook Pro.

The fix for me was to clean out the dust from inside my laptop. I removed the fan (just requires unscrewing it with a special screwdriver, like the type for installing a hard drive) and there was a giant amount of dust blocking the airflow.

Kernel_text helps regulate the computer temperature. It was trying, but the fan couldn't do its job. After this fix, I went from 500 GB of kernel_text disk usage within a few hours of computer use, to less than 2 GB.

Interestingly, this also seemed to fix the issue of disnoted and sharedfilelistd processes using too much CPU.

However, my computer didn't have massive disk usage from the CrashPlanService process, so you might have a different issue.