FreeBSD 8.4 freeze

[Руслан Бурханов]

For the last time, some of my FreeBSD servers intermittently freeze,
meaning that their normal network services stop responding (Servers
unreachable over network,
including ping). IPMI over the same network continues to work on these
frozen boxes. I am successfully rebooting the frozen services via IPMI, and
I can see the last console screen via IPMI prior to the freeze. That last
console screen does not contain any kind of "panic" output from the kernel.

I don't see any suspicious entries in /var/log/messages or console.log after
rebooting.

The problem is as dedicated servers and on platforms over KVM hosts.

First assumption, the problem is in the kernel. But i reproduced the
situation as at 8.4 RELEASE (various patchset's), and 8.4 STABLE.

Kernel with "DEBUG=-g, KDB, KDB_TRACE". And it is no kernel panic.

Thank you for any advance.