Tracking if disk is busy

Bill Moran wmoran at
Thu Jun 22 22:52:51 UTC 2006

Matt Ruzicka <matt at> wrote:

> We've got a couple servers that appear to have particularly busy disks and 
> I was trying to determine if there is a way to more easily poll this data 
> for tracking.
> I'm not sure if this is one of those can't see the forest for the trees 
> issues or not, but the only means that I am familiar with to see the 
> percentage of time the disk is busy is to run 'systat -vmstat'.  I was 
> hoping for something more concise that I could run periodically and maybe 
> even graph (realizing that watching this might well distort the results).
> It appears that iostat on Solaris gives this information, but I can't seem 
> to mimic this functionality with FreeBSD.
> Are there other ways in FreeBSD to pull the percentage of time the disk is 
> busy?

If you instal net-snmp you can get various statistics via snmp.  We use
mrtg to graph them.  Disk activity is but one.

I haven't messed with the builtin snmp stuff that comes with 6.x, but I've
got in on my list to investigate and see if it's ready to replace the
net-snmp port.

Bill Moran

You will give me the Ring freely?  In place of the Dark Lord you will set
up a Queen.  And I shall not be dark, but beautiful and terrible as the
Morning and the Night!  Fair as the Sea and the Sun and the Snow upon the
Mountain!  Dreadful as the Storm and the Lightning!  Stronger than the
foundations of the earth.  All shall love me and despair!


More information about the freebsd-questions mailing list