/var/log/messages output after the machine rebooted itself a minute or so after one of the freezes while testing: Apr 12 17:49:06 amd645200 kernel: Fatal trap 12: page fault while in kernel mode Apr 12 17:49:06 amd645200 kernel: cpuid = 0; apic id = 00 Apr 12 17:49:06 amd645200 kernel: fault virtual address = 0x20 Apr 12 17:49:06 amd645200 kernel: fault code = supervisor read data, page not present Apr 12 17:49:06 amd645200 kernel: instruction pointer = 0x8:0xffffffff807ba349 Apr 12 17:49:06 amd645200 kernel: stack pointer = 0x10:0xffffffffc75849f0 Apr 12 17:49:06 amd645200 kernel: frame pointer = 0x10:0xffffff0003e96350 Apr 12 17:49:06 amd645200 kernel: code segment = base 0x0, limit 0xfffff, type 0x1b Apr 12 17:49:06 amd645200 kernel: = DPL 0, pres 1, long 1, def32 0, gran 1 Apr 12 17:49:06 amd645200 kernel: processor eflags = interrupt enabled, resume, IOPL = 0 Apr 12 17:49:06 amd645200 kernel: current process = 2651 (true) Apr 12 17:49:06 amd645200 kernel: trap number = 12 Apr 12 17:49:06 amd645200 kernel: panic: page fault Apr 12 17:49:06 amd645200 kernel: cpuid = 0 Apr 12 17:49:06 amd645200 kernel: Uptime: 24m5s =================================================================================== kgdb output from a coredump that was produced. This case was a little different as the machine was hanging for several minutes without rebooting so I hard powered it off, but when it came back up it had this dump. It may not be related to the problem: [GDB will not be able to debug user-mode threads: /usr/lib/libthread_db.so: Undefined symbol "ps_pglobal_lookup"] GNU gdb 6.1.1 [FreeBSD] Copyright 2004 Free Software Foundation, Inc. GDB is free software, covered by the GNU General Public License, and you are welcome to change it and/or distribute copies of it under certain conditions. Type "show copying" to see the conditions. There is absolutely no warranty for GDB. Type "show warranty" for details. This GDB was configured as "amd64-marcel-freebsd". There is no member named pathname. Reading symbols from /boot/kernel/zfs.ko...Reading symbols from /boot/kernel/zfs.ko.symbols...done. done. Loaded symbols for /boot/kernel/zfs.ko Reading symbols from /boot/kernel/ipfw.ko...Reading symbols from /boot/kernel/ipfw.ko.symbols...done. done. Loaded symbols for /boot/kernel/ipfw.ko Reading symbols from /boot/kernel/radeon.ko...Reading symbols from /boot/kernel/radeon.ko.symbols...done. done. Loaded symbols for /boot/kernel/radeon.ko Reading symbols from /boot/kernel/drm.ko...Reading symbols from /boot/kernel/drm.ko.symbols...done. done. Loaded symbols for /boot/kernel/drm.ko Unread portion of the kernel message buffer: Fatal trap 12: page fault while in kernel mode cpuid = 1; apic id = 01 fault virtual address = 0x20 fault code = supervisor read data, page not present instruction pointer = 0x8:0xffffffff807ba349 stack pointer = 0x10:0xffffffffc74179f0 frame pointer = 0x10:0xffffff00030ea9f0 code segment = base 0x0, limit 0xfffff, type 0x1b = DPL 0, pres 1, long 1, def32 0, gran 1 processor eflags = interrupt enabled, resume, IOPL = 0 current process = 3250 (true) trap number = 12 panic: page fault cpuid = 1 Uptime: 38m57s Physical memory: 2035 MB Dumping 529 MB: 514 498 482 466 450 434 418 402 386 370 354 338 322 306 290 274 258 242 226 210 194 178 162 146 130 114 98 82 66 50 34 18 2 #0 doadump () at pcpu.h:194 194 __asm __volatile("movq %%gs:0,%0" : "=r" (td)); (kgdb) bt full #0 doadump () at pcpu.h:194 No locals. #1 0x0000000000000004 in ?? () No symbol table info available. #2 0xffffffff804b36e0 in boot (howto=260) at /usr/src/sys/kern/kern_shutdown.c:418 _ep = (struct eventhandler_entry *) 0x0 _el = (struct eventhandler_list *) 0xffffff0001b00900 first_buf_printf = 1 #3 0xffffffff804b3afd in panic (fmt=0x104
) at /usr/src/sys/kern/kern_shutdown.c:572 td = (struct thread *) 0xffffff00030ea9f0 bootopt = Variable "bootopt" is not available. (kgdb) list *0xffffffff804b36e0 0xffffffff804b36e0 is in boot (/usr/src/sys/kern/kern_shutdown.c:418). 413 414 /* XXX This doesn't disable interrupts any more. Reconsider? */ 415 splhigh(); 416 417 if ((howto & (RB_HALT|RB_DUMP)) == RB_DUMP && !cold && !dumping) 418 doadump(); 419 420 /* Now that we're going to really halt the system... */ 421 EVENTHANDLER_INVOKE(shutdown_final, howto); 422 (kgdb) list *0xffffffff804b3afd 0xffffffff804b3afd is in panic (/usr/src/sys/kern/kern_shutdown.c:537). 532 else { 533 panicstr = fmt; 534 newpanic = 1; 535 } 536 537 va_start(ap, fmt); 538 if (newpanic) { 539 (void)vsnprintf(buf, sizeof(buf), fmt, ap); 540 panicstr = buf; 541 printf("panic: %s\n", buf);