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mpstat -P ALL shows high %wa time on a single core from an 8 core CPU and I'm trying to figure out what's writing to disk. So how can I figure out what is running on that CPU core?

Phil Frost
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Anthony Miller
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2 Answers2

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PSR column in output of :

ps -eLF

will show you PIDs on each core.

tonioc
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  • Thanks! The accepted answer with iotop did not help in my case (a stuck NFS mount), but this answer did, combined with awk to filter by core number: `ps -eLF | awk '$9 == 4'` – Onnonymous Jan 03 '22 at 10:01
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  • Run iotop and will show processes writing on disk.

Press a in it to top the most greedy process.

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  • lsof The following will return a list of all files that are open for writing:**

lsof | grep -e "[[:digit:]]\+w"

Ruslan Gerasimov
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