On Mon, 12 Jan 2009, Garance A Drosihn wrote:
He is not eager to do a whole lot of experiments to track down the problem, since this is happening on busy production machines and he can't afford to have a lot of downtime on them (especially now that the semester at RPI has started up). The systems have some large (2 TB) filesystems on them, and the lockups occur in high disk-I/O situations. He's seeing the problem on one system which is a dual CPU quad-core xeon, and another which is a 64 bit P4 with hyperthreading. The one thing in common between the two setups is that the boot drives + a 3ware controller (with its array of RAID disks) is moved from one machine to the other one:
I think playing the combinatorics game on compile-time flags, kernel features, etc, is probably not the best way to go about debugging this. Instead, I'd debug this as a kernel hang by breaking into the debugger once it occurs, if possible, and ideally on a serial console. Often times hangs can be debugged looking solely at DDB output, or if possible, a crash dump.
Robert N M Watson Computer Laboratory University of Cambridge _______________________________________________ freebsd-stable@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to "freebsd-stable-unsubscr...@freebsd.org"
