how to fix "interrupt storm"

[perryh at pluto.rain.com]

"Paul B. Mahol" <onemda at gmail.com> wrote:
> On 5/8/09, perryh at pluto.rain.com <perryh at pluto.rain.com> wrote:
> > What, exactly, is an "interrupt storm", and how do I fix it?
...
> >   interrupt storm detected on "irq9:"; throttling interrupt source
> >   interrupt storm detected on "irq9:"; throttling interrupt source
> >   interrupt storm detected on "irq9:"; throttling interrupt source
> >   interrupt storm detected on "irq9:"; throttling interrupt source
> >   interrupt storm detected on "irq9:"; throttling interrupt source
> >   ad6: FAILURE - SET_MULTI status=51<READY,DSC,ERROR> error=4<ABORTED>
> >   ad6: TIMEOUT - READ_DMA retrying (1 retry left) LBA=136936
> >
> > etc. etc. until I killed it with ^C.  (Just entering "q", to cause
> > more(1) to exit and presumably stop od(1) with a SIGPIPE, did not
> > stop the spew of messages.)
> >
> > What does this indicate?  Hardware problems?  Bad configuration?
> > Something else?
>
> Output of "vmstat -i"?

$ vmstat -i
interrupt                          total       rate
irq0: clk                      497386851       1004
irq1: atkbd0                        2491          0
irq3: xl0                           2030          0
irq6: fdc0                            11          0
irq7: ppbus0 ppc0                      1          0
irq8: rtc                       63654324        128
irq9: uhci0+                      166216          0
irq14: ata0                       369620          0
irq15: ata1                          691          0
Total                          561582235       1133