Fresh 7.0 Install: Fatal Trap 12 panic when put under load

[Michael Grant]

I have been having what seems like similar panics.  I too cannot
manage to get a crash dump, neither classic style nor minidump.  Nor
can I get it to work with DDB, there seems to be a problem with DDB
and my Geom mirror.

Kris recommended I up kmem_size which I have done (twice now) and
since the last time I upped it, the machine has not crashed again
(yet?).  For the moment, I'm hoping things are stable.

In /boot/loader.conf, I currently have the following:

vm.kmem_size=1G
vm.kmem_size_max=1G
vm.kmem_size_scale=2

and in my kernel conf file I have:

options         KVA_PAGES=512

Here's what top says currently:

last pid: 57367;  load averages:  0.56,  0.54,  0.61
up 2+10:16:57  15:50:55
407 processes: 6 running, 378 sleeping, 2 zombie, 21 waiting
CPU states:  0.1% user,  0.0% nice,  2.3% system,  0.7% interrupt, 97.0% idle
Mem: 1309M Active, 1291M Inact, 497M Wired, 155M Cache, 199M Buf, 7408K Free
Swap: 9541M Total, 1628K Used, 9540M Free

Is this a heavily loaded machine?  It's using a lot of memory, but
it's mostly idle.

I have 2 sticks of double-sided memory (4gig total) in the box.  The
SuperMicro documentation recommends using single sided sticks for 6 or
more sticks.

I feel for you John, I've lost many nights sleep in the last couple
weeks trying to understand why this production box was crashing.  I
was really surprised to see this start happening, normally my freebsd
boxes have uptimes in terms of years, not hours.

Michael Grant