silent disk drive

Polytropon freebsd at
Sat Jun 15 12:33:00 UTC 2019

On Sat, 15 Jun 2019 02:01:34 +0200, Matthias R. wrote:
> Hello,
> thanx for having this group, my question: how do I find out which
> process is writing every minute to the disk drive so that it wakes
> up the hard drive. I am using a gerneric installation 12.0 and types 
> camcontrol sleep ada0
> Every time I do that it will wake up afer some 60 sec. and writes
> somewhere I cannot find out.
> Do you know something helpful? It#s that I like the silence to read...

Because actual disk writes are "many levels down" from file
handling within programs, it's not trivial to tell, but there
are several ways to find out. Tools like lsof, top -St, htop
can give you an impression of what programs cause disk activity.
But always remember that actual disk activity is managed by the
OS (asynchronous, scheduled, etc.), and just because the kernel
issues a "flush this to disk" instruction, it doesn't imply that
the disk will do it in the exact same moment. :-)

Additionally, minimize your workload as much as possible first,
then begin starting services and programs. This makes sure you
have better changes identifying the program that causes the disk

Finally, you can use smartctl to check if the disk has been
(accidentally) put into some case of "self-testing cycle" which
causes activity independent from OS and programs.

Good luck!

Magdeburg, Germany
Happy FreeBSD user since 4.0
Andra moi ennepe, Mousa, ...

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