# The disk is not calm now



## sw2wolf (Nov 11, 2014)

Since I upgraded to 9.3 from 9.1, the hard disk light always twinkles. It is so quiet in 9.1. How can I know which process(es) are writing to the disk?

Regards!


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## bthomson (Nov 11, 2014)

I recall trying to find this information quite a while ago. My memory may be failing me, but what I recall is that you can use `fstat` to find the processes that are writing to your disks (and the files they're writing to) for most filesystems. Except ZFS. If it's ZFS, then you have to use some convoluted debugging method to find this information. In my case, ZFS was the culprit, and it turned out to be such a pain in the behind that I gave up and stopped worrying about it.

Hopefully the experts will chime in to correct my errors.

EDIT: Looking over the output of `fstat` on my box, it seems like maybe you get the process and the filesystem, but not the exact file path for ZFS. Maybe finding the exact path is what I'm remembering being a pain.


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## junovitch@ (Nov 11, 2014)

Anything with "stat" in it is a good place to start.  gstat for example is a good way to see activity for each GEOM providers and can be a good way to look at  general disk activity.  As previously mentioned, fstat can show what files are open when it runs.  If you want something real time, try `kldload dtraceall` and then either /usr/share/dtrace/toolkit/opensnoop or /usr/share/dtrace/hotopen.


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