LSI/amr driver controller cache problem?

[Patrick M. Hausen]

Hi, all!

On Fri, Sep 01, 2006 at 11:15:37AM -0600, Scott Long wrote:

> It is very arguably a bug in the LSI firmware if it is actually dumping
> its cache when a PCI reset occurs, especially if a battery unit is
> present.  However, I seriously doubt that you will get anyone at LSI to
> listen to this problem.  Do you get any messages on the console at
> shutdown about the amr driver flushing the cache?

Just verified - yes:

amr0: flushing cache...done
amr1: flushing cache...done

> Also, check the cache
> setting on the drives itself. Maybe the drives are loosing power or
> getting reset while data is in their cache.

I'm starting to suspect something like this. The controller's setting
for the individual drives' caches is "OFF". But these (Seagate ST3500841NS)
would not be the first ATA/SATA drives to "lie" about their cache for
"performance".

>From the settings that are readily available through the controller's
and other knobs, I eliminated all: controller cache policy: "WTHRU",
drive cache: "OFF", Softupdates: disabled (!). Just to be sure.

Installworld, reboot, *bang* unexpected file system inconsistency,
run fsck manually ...

Any ideas? I'll invest some time researching other people's reports
about my particular disk drives. Maybe there's a DOS/Windows tool
to disable their cache permanently ...

There's a small chance that actually setting the drives' caches
to "ON" will help. If the controller is intelligent enough to issue
"flush cache" commands to the individual drives and if it is
so clever that it only issues this command when the cache is configured
"ON". ;-)

Thanks,

Patrick M. Hausen
Leiter Netzwerke und Sicherheit
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