top io mode

Adam Vande More amvandemore at
Thu Nov 25 20:28:38 UTC 2010

On Thu, Nov 25, 2010 at 2:08 PM, Jeremy Chadwick
<freebsd at>wrote:

> >  Well the top bug didn't seem to resolve my actual issue and yes it it a
> > complete ZFS system.  Problem is that the HD activity indicator light is
> > constantly flickering even though should be minimal activity.  top still
> > shows no activity around the blinks, and there's no swapping happening
> > although gstat does seem to roughly match the blinks.  I can't tell what
> > your patch does, would it enable me to see what's touching the disk?
> Please try using gstat(8) instead.

Like I said gstat shows activity, but I have no way find what process is
causing the activity unless there is some hidden gstat option I'm unaware

to be more clear, if I have top -m io in one terminal, I see no movement in
the READ/WRITE columns.

while polling gstat output I captured an IO "spike"

the percent busy is at 0.00 for every entry with the exception of these

Adam Vande More

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