Identifying disk activity

Adam Vande More amvandemore at
Sun Aug 28 06:15:03 UTC 2011

On Sun, Aug 28, 2011 at 12:30 AM, Polytropon <freebsd at> wrote:

> I am not sure this is related to a program, but I'd like to
> find it out. As FreeBSD's I/O subsystem does not work in
> real-time, I cannot conclude from actual program file I/O
> to physical disk I/O.
> Is there a way to force "synchronous disk activity"?

well there is the mount -o sync option.

> My idea is to watch open files and running programs as
> precise as possible (as root: "top -St -s 0"). Which
> tools (e. g. top, htop, lsof) would you suggest to narrow
> down _which_ program is accessing _which_ file, causing
> the sound?

"top -Hm io " has revealed pesky apps in the past for me without using mount

IIRC, you have to use procstat to find if something is using swap.

Adam Vande More

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