Interpreting MCA error output

Jeremy Chadwick freebsd at
Tue Oct 18 11:33:05 UTC 2011

On Tue, Oct 18, 2011 at 06:26:49PM +1030, Daniel O'Connor wrote:
> On 18/10/2011, at 17:49, Jeremy Chadwick wrote:
> >> That would be absolutely helpful! After all, FreeBSD is primarily a
> >> server OS, and where would one have ECC if not on servers. Being able
> >> to determine what's wrong with memory would be certainly very valuable
> >> for many admins.
> > 
> > This has been done, and it was committed a couple days ago as
> > sysutils/mcelog.  There are a couple thing about the port which bother
> > me[1], and there is one warning which can be safely ignored (I'm a
> > strong advocate of -Werror) but I do have a fix for that, but otherwise
> > it's functional.
> Do MCA log events cause anything in devd?
> It would be _super_ neat if the mcelog port installed a devd rule which emailed root@ with the human readable version of an MCA exception :)
> I suspect this wouldn't be too difficult to do for a JKH.

Why?  Most MCEs on FreeBSD will panic the machine.  I would need to go
through the MCA code to see what all gets handled elegantly, but I
imagine there isn't much.

Also, isn't devd for device removal/insertions?  This would be using
devd for something it isn't intended for.  I guess I have "moral
objections" to it.  What you're really wanting is Solaris's fmd(1m)
daemon, which I believe is also tied heavily into Solaris's smf(5)

| Jeremy Chadwick                                jdc at |
| Parodius Networking              |
| UNIX Systems Administrator                   Mountain View, CA, US |
| Making life hard for others since 1977.               PGP 4BD6C0CB |

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