RE: new utility for decoding salinfo records

Ben Woodard
2005-01-11T21:03:22Z

On Tue, 2005-01-11 at 12:53, Mark Goodwin wrote:
> On Tue, 11 Jan 2005, Ben Woodard wrote:
> > ...
> > 3) If there is a real failure, it shows up really quickly. We have all
> > sorts of SBEs or MBEs. In that case we replace the DIMM immediately.
> >
> > So does anyone with "normal world" experience have any suggestions on
> > how I should take into account the various perspectives?
> >
> > Do other people consider the isolated SBE a problem?
>
> considered normal, fully recoverable.
>
> >
> > Do other people consider 1SBE/hr on a DIMM a real problem that needs to
> > be fixed?
>
> this is a concern if the failing DIMM ends up with uncorrectable MBEs.
> Do you have any evidence that a relatively high rate of SBEs on a
> DIMM can be used to predict that MBEs are likely to start occurring?

No quite the contrary. We believed rates of SBEs in the neighborhood of
1/hr would ultimately lead to MBEs but further testing has shown that we
really don't see DIMMS with SBEs turing in MBEs.

We did replace plenty of DIMMs which did have higher rates of SBEs
simply because it takes computational time to handle a SBE and we feared
it would introduce additional time in tightly coupled in scientific
codes.

> Memory hot-unplug or a bad-page reserving strategy based on such
> prediction may be interesting.
>
> -- Mark