how to get more logging from GEOM?

[Vince Hoffman]

Jo Rhett wrote:
> About 10 days ago one of my personal machines started hanging at
> random.  This is the first bit of instability I've ever experienced on
> this machine (2+ years running)
> 
> FreeBSD triceratops.netconsonance.com 6.2-RELEASE-p11 FreeBSD
> 6.2-RELEASE-p11 #0: Wed Feb 13 06:44:57 UTC 2008    
> root at i386-builder.daemonology.net:/usr/obj/usr/src/sys/GENERIC  i386
> 
> After about 2 weeks of watching it carefully I've learned almost
> nothing.  It's not a disk failure (AFAIK) it's not cpu overheat (now
> running healthd without complaints) it's not based on any given network
> traffic...  however it does appear to accompany heavy cpu/disk
> activity.  It usually dies when indexing my websites at night (but not
> always) and it sometimes dies when compiling programs.   Just heavy disk
> isn't enough to do the job, as backups proceed without problems.   Heavy
> cpu by itself isn't enough to do it either.  But if I start compiling
> things and keep going a while, it will eventually hang.
> 
> My best guess is that geom is having a problem and locking up.  There's
> no log entry before failure to back this idea up, but I think this
> because during boot I see the following:
> 
> ad0: 286168MB <Seagate ST3300622A 3.AAH> at ata0-master UDMA100
> GEOM_MIRROR: Device gm0 created (id=575427344).
> GEOM_MIRROR: Device gm0: provider ad0 detected.
> ad1: 286168MB <Seagate ST3300622A 3.AAH> at ata0-slave UDMA100
> GEOM_MIRROR: Device gm0: provider ad1 detected.
> GEOM_MIRROR: Device gm0: provider ad1 activated.
> GEOM_MIRROR: Device gm0: provider mirror/gm0 launched.
> GEOM_MIRROR: Device gm0: rebuilding provider ad0.
> 
> Every time it is rebuilding ad0.   Every single boot in the last two weeks.
> 
> Is this any way to get more logging from geom, to confirm or deny this
> theory?
Just a guess but try kern.geom.debugflags > 0
This certainly spews out far more geom info, as to how helpful this will
be...


Vince


> 
> Is there anything else I should be looking at?
> 
> FWIW, this never happened before the p11 patch to 6.2.   I don't know if
> that is related or not.
> 
> Obviously, I can't upgrade to 6.3 if heavy cpu/disk activity kills the
> system.
> 
> No, I don't have any other insights.  I'm not prone to posting "duh help
> me please!" posts, so I'm quite a bit frustrated by this one.
>