硬件平台: Intel Atom N270 1.6G / Intel 945GSE + ICH7 / Kinston DDRII 2G / Kinston CF 4G
软件: FreeBSD 7.2R / NTPD v 4.2.4p5 / sshd
症状: 无规律死机（至少我目前么有看出来），多数情况下发生在系统运行1~2小时之间。也有持续运行12小时以上啥事也没有的。
恼火的是，系统日志里看不出什么异常，last的输出显示了一些crash。而且，down机后系统就一直挂在那等着被风干了，也不自动重启。
可能的原因：
1、硬件兼容性问题（特别是内存）
2、电源
3、散热不良
4、异常断电
5、软件问题
有空再逐一排查一下。
0:05:14, 2010年5月6日
这两天，系统运行较之前要稳定多了，几乎没有出现死机的情况。难道是因为开了空调？
通过修改/etc/syslogd.conf，将所有日志*.*输出到/var/log/all.log，看来似乎一切正常。
last命令的输出中有一些"crash"，但测试了一下，也可能是突然掉电造成的。在目前的应用中，关闭系统都是直接切断电源，所以这些"crash"说明不了啥问题。
在4月26日通过bios禁用了ACPI。不知道这两天的稳定运行是否与此有关。
贴上kernel conf和dmesg
#
# GENERIC -- Generic kernel configuration file for FreeBSD/i386
#
# For more information on this file, please read the handbook section on
# Kernel Configuration Files:
#
#
http://www.FreeBSD.org/doc/en_US.ISO8859-1/books/handbook/kernelconfig-config.html#
# The handbook is also available locally in /usr/share/doc/handbook
# if you've installed the doc distribution, otherwise always see the
# FreeBSD World Wide Web server (
http://www.FreeBSD.org/) for the
# latest information.
#
# An exhaustive list of options and more detailed explanations of the
# device lines is also present in the ../../conf/NOTES and NOTES files.
# If you are in doubt as to the purpose or necessity of a line, check first
# in NOTES.
#
# $FreeBSD: src/sys/i386/conf/GENERIC,v 1.474.2.17.2.1 2009/04/15 03:14:26 kensmith Exp $
#cpu I486_CPU
#cpu I586_CPU
cpu I686_CPU
#ident GENERIC
ident PPSKERNEL
# To statically compile in device wiring instead of /boot/device.hints
#hints "GENERIC.hints" # Default places to look for devices.
makeoptions DEBUG=-g # Build kernel with gdb(1) debug symbols
options PPS_SYNC
options SCHED_ULE # ULE scheduler
options PREEMPTION # Enable kernel thread preemption
options INET # InterNETworking
options INET6 # IPv6 communications protocols
options SCTP # Stream Control Transmission Protocol
options FFS # Berkeley Fast Filesystem
options SOFTUPDATES # Enable FFS soft updates support
options UFS_ACL # Support for access control lists
options UFS_DIRHASH # Improve performance on big directories
options UFS_GJOURNAL # Enable gjournal-based UFS journaling
options MD_ROOT # MD is a potential root device
options NFSCLIENT # Network Filesystem Client
options NFSSERVER # Network Filesystem Server
options NFSLOCKD # Network Lock Manager
options NFS_ROOT # NFS usable as /, requires NFSCLIENT
options MSDOSFS # MSDOS Filesystem
options CD9660 # ISO 9660 Filesystem
options PROCFS # Process filesystem (requires PSEUDOFS)
options PSEUDOFS # Pseudo-filesystem framework
options GEOM_PART_GPT # GUID Partition Tables.
options GEOM_LABEL # Provides labelization
options COMPAT_43TTY # BSD 4.3 TTY compat [KEEP THIS!]
options COMPAT_FREEBSD4 # Compatible with FreeBSD4
options COMPAT_FREEBSD5 # Compatible with FreeBSD5
options COMPAT_FREEBSD6 # Compatible with FreeBSD6
options SCSI_DELAY=5000 # Delay (in ms) before probing SCSI
options KTRACE # ktrace(1) support
options STACK # stack(9) support
options SYSVSHM # SYSV-style shared memory
options SYSVMSG # SYSV-style message queues
options SYSVSEM # SYSV-style semaphores
options _KPOSIX_PRIORITY_SCHEDULING # POSIX P1003_1B real-time extensions
options KBD_INSTALL_CDEV # install a CDEV entry in /dev
options ADAPTIVE_GIANT # Giant mutex is adaptive.
options STOP_NMI # Stop CPUS using NMI instead of IPI
options AUDIT # Security event auditing
#options KDTRACE_HOOKS # Kernel DTrace hooks
# To make an SMP kernel, the next two lines are needed
options SMP # Symmetric MultiProcessor Kernel
device apic # I/O APIC
# CPU frequency control
device cpufreq
# Bus support.
device eisa
device pci
# Floppy drives
device fdc
# ATA and ATAPI devices
device ata
device atadisk # ATA disk drives
device ataraid # ATA RAID drives
device atapicd # ATAPI CDROM drives
device atapifd # ATAPI floppy drives
device atapist # ATAPI tape drives
options ATA_STATIC_ID # Static device numbering
# SCSI Controllers
device ahb # EISA AHA1742 family
device ahc # AHA2940 and onboard AIC7xxx devices
options AHC_REG_PRETTY_PRINT # Print register bitfields in debug
# output. Adds ~128k to driver.
device ahd # AHA39320/29320 and onboard AIC79xx devices
options AHD_REG_PRETTY_PRINT # Print register bitfields in debug
# output. Adds ~215k to driver.
device amd # AMD 53C974 (Tekram DC-390(T))
device hptiop # Highpoint RocketRaid 3xxx series
device isp # Qlogic family
#device ispfw # Firmware for QLogic HBAs- normally a module
device mpt # LSI-Logic MPT-Fusion
#device ncr # NCR/Symbios Logic
device sym # NCR/Symbios Logic (newer chipsets + those of `ncr')
device trm # Tekram DC395U/UW/F DC315U adapters
device adv # Advansys SCSI adapters
device adw # Advansys wide SCSI adapters
device aha # Adaptec 154x SCSI adapters
device aic # Adaptec 15[012]x SCSI adapters, AIC-6[23]60.
device bt # Buslogic/Mylex MultiMaster SCSI adapters
device ncv # NCR 53C500
device nsp # Workbit Ninja SCSI-3
device stg # TMC 18C30/18C50
# SCSI peripherals
device scbus # SCSI bus (required for SCSI)
device ch # SCSI media changers
device da # Direct Access (disks)
device sa # Sequential Access (tape etc)
device cd # CD
device pass # Passthrough device (direct SCSI access)
device ses # SCSI Environmental Services (and SAF-TE)
# RAID controllers interfaced to the SCSI subsystem
device amr # AMI MegaRAID
device arcmsr # Areca SATA II RAID
device asr # DPT SmartRAID V, VI and Adaptec SCSI RAID
device ciss # Compaq Smart RAID 5*
device dpt # DPT Smartcache III, IV - See NOTES for options
device hptmv # Highpoint RocketRAID 182x
device hptrr # Highpoint RocketRAID 17xx, 22xx, 23xx, 25xx
device iir # Intel Integrated RAID
device ips # IBM (Adaptec) ServeRAID
device mly # Mylex AcceleRAID/eXtremeRAID
device twa # 3ware 9000 series PATA/SATA RAID
# RAID controllers
device aac # Adaptec FSA RAID
device aacp # SCSI passthrough for aac (requires CAM)
device ida # Compaq Smart RAID
device mfi # LSI MegaRAID SAS
device mlx # Mylex DAC960 family
device pst # Promise Supertrak SX6000
device twe # 3ware ATA RAID
# atkbdc0 controls both the keyboard and the PS/2 mouse
device atkbdc # AT keyboard controller
device atkbd # AT keyboard
device psm # PS/2 mouse
device kbdmux # keyboard multiplexer
device vga # VGA video card driver
device splash # Splash screen and screen saver support
# syscons is the default console driver, resembling an SCO console
device sc
device agp # support several AGP chipsets
# Power management support (see NOTES for more options)
#device apm
# Add suspend/resume support for the i8254.
device pmtimer
# PCCARD (PCMCIA) support
# PCMCIA and cardbus bridge support
device cbb # cardbus (yenta) bridge
device pccard # PC Card (16-bit) bus
device cardbus # CardBus (32-bit) bus
# Serial (COM) ports
device sio # 8250, 16[45]50 based serial ports
device uart # Generic UART driver
# Parallel port
device ppc
device ppbus # Parallel port bus (required)
device lpt # Printer
device plip # TCP/IP over parallel
device ppi # Parallel port interface device
#device vpo # Requires scbus and da
# If you've got a "dumb" serial or parallel PCI card that is
# supported by the puc(4) glue driver, uncomment the following
# line to enable it (connects to sio, uart and/or ppc drivers):
#device puc
# PCI Ethernet NICs.
device de # DEC/Intel DC21x4x (``Tulip'')
device em # Intel PRO/1000 Gigabit Ethernet Family
device igb # Intel PRO/1000 PCIE Server Gigabit Family
device ixgb # Intel PRO/10GbE Ethernet Card
device le # AMD Am7900 LANCE and Am79C9xx PCnet
device txp # 3Com 3cR990 (``Typhoon'')
device vx # 3Com 3c590, 3c595 (``Vortex'')
# PCI Ethernet NICs that use the common MII bus controller code.
# NOTE: Be sure to keep the 'device miibus' line in order to use these NICs!
device miibus # MII bus support
device age # Attansic/Atheros L1 Gigabit Ethernet
device ale # Atheros AR8121/AR8113/AR8114 Ethernet
device bce # Broadcom BCM5706/BCM5708 Gigabit Ethernet
device bfe # Broadcom BCM440x 10/100 Ethernet
device bge # Broadcom BCM570xx Gigabit Ethernet
device dc # DEC/Intel 21143 and various workalikes
device et # Agere ET1310 10/100/Gigabit Ethernet
device fxp # Intel EtherExpress PRO/100B (82557, 82558)
device jme # JMicron JMC250 Gigabit/JMC260 Fast Ethernet
device lge # Level 1 LXT1001 gigabit Ethernet
device msk # Marvell/SysKonnect Yukon II Gigabit Ethernet
device nfe # nVidia nForce MCP on-board Ethernet
device nge # NatSemi DP83820 gigabit Ethernet
#device nve # nVidia nForce MCP on-board Ethernet Networking
device pcn # AMD Am79C97x PCI 10/100 (precedence over 'le')
device re # RealTek 8139C+/8169/8169S/8110S
device rl # RealTek 8129/8139
device sf # Adaptec AIC-6915 (``Starfire'')
device sis # Silicon Integrated Systems SiS 900/SiS 7016
device sk # SysKonnect SK-984x & SK-982x gigabit Ethernet
device ste # Sundance ST201 (D-Link DFE-550TX)
device stge # Sundance/Tamarack TC9021 gigabit Ethernet
device ti # Alteon Networks Tigon I/II gigabit Ethernet
device tl # Texas Instruments ThunderLAN
device tx # SMC EtherPower II (83c170 ``EPIC'')
device vge # VIA VT612x gigabit Ethernet
device vr # VIA Rhine, Rhine II
device wb # Winbond W89C840F
device xl # 3Com 3c90x (``Boomerang'', ``Cyclone'')
# ISA Ethernet NICs. pccard NICs included.
device cs # Crystal Semiconductor CS89x0 NIC
# 'device ed' requires 'device miibus'
device ed # NE[12]000, SMC Ultra, 3c503, DS8390 cards
device ex # Intel EtherExpress Pro/10 and Pro/10+
device ep # Etherlink III based cards
device fe # Fujitsu MB8696x based cards
device ie # EtherExpress 8/16, 3C507, StarLAN 10 etc.
device sn # SMC's 9000 series of Ethernet chips
device xe # Xircom pccard Ethernet
# Wireless NIC cards
device wlan # 802.11 support
device wlan_wep # 802.11 WEP support
device wlan_ccmp # 802.11 CCMP support
device wlan_tkip # 802.11 TKIP support
device wlan_amrr # AMRR transmit rate control algorithm
device wlan_scan_ap # 802.11 AP mode scanning
device wlan_scan_sta # 802.11 STA mode scanning
device an # Aironet 4500/4800 802.11 wireless NICs.
device ath # Atheros pci/cardbus NIC's
device ath_hal # Atheros HAL (Hardware Access Layer)
options AH_SUPPORT_AR5416 # enable AR5416 tx/rx descriptors
device ath_rate_sample # SampleRate tx rate control for ath
device awi # BayStack 660 and others
device ral # Ralink Technology RT2500 wireless NICs.
device wi # WaveLAN/Intersil/Symbol 802.11 wireless NICs.
#device wl # Older non 802.11 Wavelan wireless NIC.
# Pseudo devices.
device loop # Network loopback
device random # Entropy device
device ether # Ethernet support
device sl # Kernel SLIP
device ppp # Kernel PPP
device tun # Packet tunnel.
device pty # Pseudo-ttys (telnet etc)
device md # Memory "disks"
device gif # IPv6 and IPv4 tunneling
device faith # IPv6-to-IPv4 relaying (translation)
device firmware # firmware assist module
# The `bpf' device enables the Berkeley Packet Filter.
# Be aware of the administrative consequences of enabling this!
# Note that 'bpf' is required for DHCP.
device bpf # Berkeley packet filter
# USB support
device uhci # UHCI PCI->USB interface
device ohci # OHCI PCI->USB interface
device ehci # EHCI PCI->USB interface (USB 2.0)
device usb # USB Bus (required)
#device udbp # USB Double Bulk Pipe devices
device ugen # Generic
device uhid # "Human Interface Devices"
device ukbd # Keyboard
device ulpt # Printer
device umass # Disks/Mass storage - Requires scbus and da
device ums # Mouse
device ural # Ralink Technology RT2500USB wireless NICs
device rum # Ralink Technology RT2501USB wireless NICs
device urio # Diamond Rio 500 MP3 player
device uscanner # Scanners
# USB Serial devices
device ucom # Generic com ttys
device uark # Technologies ARK3116 based serial adapters
device ubsa # Belkin F5U103 and compatible serial adapters
device ubser # BWCT console serial adapters
device uftdi # For FTDI usb serial adapters
device uipaq # Some WinCE based devices
device uplcom # Prolific PL-2303 serial adapters
device uslcom # SI Labs CP2101/CP2102 serial adapters
device uvisor # Visor and Palm devices
device uvscom # USB serial support for DDI pocket's PHS
# USB Ethernet, requires miibus
device aue # ADMtek USB Ethernet
device axe # ASIX Electronics USB Ethernet
device cdce # Generic USB over Ethernet
device cue # CATC USB Ethernet
device kue # Kawasaki LSI USB Ethernet
device rue # RealTek RTL8150 USB Ethernet
# FireWire support
device firewire # FireWire bus code
device sbp # SCSI over FireWire (Requires scbus and da)
device fwe # Ethernet over FireWire (non-standard!)
device fwip # IP over FireWire (RFC 2734,3146)
device dcons # Dumb console driver
device dcons_crom # Configuration ROM for dcons
Copyright (c) 1992-2009 The FreeBSD Project.
Copyright (c) 1979, 1980, 1983, 1986, 1988, 1989, 1991, 1992, 1993, 1994
The Regents of the University of California. All rights reserved.
FreeBSD is a registered trademark of The FreeBSD Foundation.
FreeBSD 7.2-RELEASE #0: Sat Apr 24 03:00:43 CST 2010
root@:/usr/obj/usr/src/sys/PPSKERNELTimecounter "i8254" frequency 1193182 Hz quality 0
CPU: Intel(R) Atom(TM) CPU N270 @ 1.60GHz (1596.01-MHz 686-class CPU)
Origin = "GenuineIntel" Id = 0x106c2 Stepping = 2
Features=0xbfe9fbff<FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR,PGE,MCA,CMOV,PAT,CLFLUSH,DTS,ACPI,MMX,FXSR,SSE,SSE2,SS,HTT,TM,PBE>
Features2=0x40c39d<SSE3,DTES64,MON,DS_CPL,EST,TM2,SSSE3,xTPR,PDCM,<b22>>
AMD Features=0x100000<NX>
AMD Features2=0x1<LAHF>
Logical CPUs per core: 2
real memory = 1064239104 (1014 MB)
avail memory = 1027747840 (980 MB)
MPTable: <OEM00000 PROD00000000>
ioapic0: Changing APIC ID to 2
ioapic0: Assuming intbase of 0
ioapic0 <Version 2.0> irqs 0-23 on motherboard
kbd1 at kbdmux0
pcib0: <MPTable Host-PCI bridge> pcibus 0 on motherboard
pci0: <PCI bus> on pcib0
vgapci0: <VGA-compatible display> port 0xff00-0xff07 mem 0xfdf00000-0xfdf7ffff,0xd0000000-0xdfffffff,0xfdf80000-0xfdfbffff irq 16 at device 2.0 on pci0
agp0: <Intel 945GME SVGA controller> on vgapci0
agp0: detected 7932k stolen memory
agp0: aperture size is 256M
vgapci1: <VGA-compatible display> mem 0xfde80000-0xfdefffff at device 2.1 on pci0
pcib1: <MPTable PCI-PCI bridge> irq 16 at device 28.0 on pci0
pci1: <PCI bus> on pcib1
re0: <RealTek 8168/8168B/8168C/8168CP/8168D/8111B/8111C/8111CP PCIe Gigabit Ethernet> port 0x9e00-0x9eff mem 0xfd9ff000-0xfd9fffff,0xfd6f0000-0xfd6fffff irq 16 at device 0.0 on pci1
re0: Using 1 MSI messages
re0: Chip rev. 0x3c000000
re0: MAC rev. 0x00400000
miibus0: <MII bus> on re0
rgephy0: <RTL8169S/8110S/8211B media interface> PHY 1 on miibus0
rgephy0: 10baseT, 10baseT-FDX, 100baseTX, 100baseTX-FDX, 1000baseT, 1000baseT-FDX, auto
re0: Ethernet address: 00:50:c2:1e:fb:89
re0: [FILTER]
pcib2: <MPTable PCI-PCI bridge> irq 17 at device 28.1 on pci0
pci2: <PCI bus> on pcib2
re1: <RealTek 8168/8168B/8168C/8168CP/8168D/8111B/8111C/8111CP PCIe Gigabit Ethernet> port 0xde00-0xdeff mem 0xfd5ff000-0xfd5fffff,0xfd4f0000-0xfd4fffff irq 17 at device 0.0 on pci2
re1: Using 1 MSI messages
re1: Chip rev. 0x3c000000
re1: MAC rev. 0x00400000
miibus1: <MII bus> on re1
rgephy1: <RTL8169S/8110S/8211B media interface> PHY 1 on miibus1
rgephy1: 10baseT, 10baseT-FDX, 100baseTX, 100baseTX-FDX, 1000baseT, 1000baseT-FDX, auto
re1: Ethernet address: 00:50:c2:1e:fb:8a
re1: [FILTER]
pcib3: <MPTable PCI-PCI bridge> irq 18 at device 28.2 on pci0
pci3: <PCI bus> on pcib3
re2: <RealTek 8168/8168B/8168C/8168CP/8168D/8111B/8111C/8111CP PCIe Gigabit Ethernet> port 0xce00-0xceff mem 0xfddff000-0xfddfffff,0xfdcf0000-0xfdcfffff irq 18 at device 0.0 on pci3
re2: Using 1 MSI messages
re2: Chip rev. 0x3c000000
re2: MAC rev. 0x00400000
miibus2: <MII bus> on re2
rgephy2: <RTL8169S/8110S/8211B media interface> PHY 1 on miibus2
rgephy2: 10baseT, 10baseT-FDX, 100baseTX, 100baseTX-FDX, 1000baseT, 1000baseT-FDX, auto
re2: Ethernet address: 00:50:c2:1e:fb:8b
re2: [FILTER]
pcib4: <MPTable PCI-PCI bridge> irq 19 at device 28.3 on pci0
pci4: <PCI bus> on pcib4
re3: <RealTek 8168/8168B/8168C/8168CP/8168D/8111B/8111C/8111CP PCIe Gigabit Ethernet> port 0xbe00-0xbeff mem 0xfdbff000-0xfdbfffff,0xfdaf0000-0xfdafffff irq 19 at device 0.0 on pci4
re3: Using 1 MSI messages
re3: Chip rev. 0x3c000000
re3: MAC rev. 0x00400000
miibus3: <MII bus> on re3
rgephy3: <RTL8169S/8110S/8211B media interface> PHY 1 on miibus3
rgephy3: 10baseT, 10baseT-FDX, 100baseTX, 100baseTX-FDX, 1000baseT, 1000baseT-FDX, auto
re3: Ethernet address: 00:50:c2:1e:fb:8c
re3: [FILTER]
uhci0: <UHCI (generic) USB controller> port 0xfe00-0xfe1f irq 23 at device 29.0 on pci0
uhci0: [GIANT-LOCKED]
uhci0: [ITHREAD]
usb0: <UHCI (generic) USB controller> on uhci0
usb0: USB revision 1.0
uhub0: <Intel UHCI root hub, class 9/0, rev 1.00/1.00, addr 1> on usb0
uhub0: 2 ports with 2 removable, self powered
uhci1: <UHCI (generic) USB controller> port 0xfd00-0xfd1f irq 19 at device 29.1 on pci0
uhci1: [GIANT-LOCKED]
uhci1: [ITHREAD]
usb1: <UHCI (generic) USB controller> on uhci1
usb1: USB revision 1.0
uhub1: <Intel UHCI root hub, class 9/0, rev 1.00/1.00, addr 1> on usb1
uhub1: 2 ports with 2 removable, self powered
uhci2: <UHCI (generic) USB controller> port 0xfc00-0xfc1f irq 18 at device 29.2 on pci0
uhci2: [GIANT-LOCKED]
uhci2: [ITHREAD]
usb2: <UHCI (generic) USB controller> on uhci2
usb2: USB revision 1.0
uhub2: <Intel UHCI root hub, class 9/0, rev 1.00/1.00, addr 1> on usb2
uhub2: 2 ports with 2 removable, self powered
uhci3: <UHCI (generic) USB controller> port 0xfb00-0xfb1f irq 16 at device 29.3 on pci0
uhci3: [GIANT-LOCKED]
uhci3: [ITHREAD]
usb3: <UHCI (generic) USB controller> on uhci3
usb3: USB revision 1.0
uhub3: <Intel UHCI root hub, class 9/0, rev 1.00/1.00, addr 1> on usb3
uhub3: 2 ports with 2 removable, self powered
ehci0: <Intel 82801GB/R (ICH7) USB 2.0 controller> mem 0xfdfff000-0xfdfff3ff irq 23 at device 29.7 on pci0
ehci0: [GIANT-LOCKED]
ehci0: [ITHREAD]
usb4: waiting for BIOS to give up control
usb4: EHCI version 1.0
usb4: companion controllers, 2 ports each: usb0 usb1 usb2 usb3
usb4: <Intel 82801GB/R (ICH7) USB 2.0 controller> on ehci0
usb4: USB revision 2.0
uhub4: <Intel EHCI root hub, class 9/0, rev 2.00/1.00, addr 1> on usb4
uhub4: 8 ports with 8 removable, self powered
pcib5: <PCI-PCI bridge> at device 30.0 on pci0
pci5: <PCI bus> on pcib5
isab0: <PCI-ISA bridge> at device 31.0 on pci0
isa0: <ISA bus> on isab0
atapci0: <Intel ICH7 UDMA100 controller> port 0x1f0-0x1f7,0x3f6,0x170-0x177,0x376,0xf800-0xf80f at device 31.1 on pci0
ata0: <ATA channel 0> on atapci0
ata0: [ITHREAD]
pci0: <serial bus, SMBus> at device 31.3 (no driver attached)
cpu0 on motherboard
est0: <Enhanced SpeedStep Frequency Control> on cpu0
est: CPU supports Enhanced Speedstep, but is not recognized.
est: cpu_vendor GenuineIntel, msr 60f0c270600060f
device_attach: est0 attach returned 6
p4tcc0: <CPU Frequency Thermal Control> on cpu0
pmtimer0 on isa0
orm0: <ISA Option ROM> at iomem 0xef000-0xeffff pnpid ORM0000 on isa0
atkbdc0: <Keyboard controller (i8042)> at port 0x60,0x64 on isa0
atkbd0: <AT Keyboard> irq 1 on atkbdc0
kbd0 at atkbd0
atkbd0: [GIANT-LOCKED]
atkbd0: [ITHREAD]
ppc0: parallel port not found.
sc0: <System console> at flags 0x100 on isa0
sc0: VGA <16 virtual consoles, flags=0x300>
sio0 at port 0x3f8-0x3ff irq 4 flags 0x10 on isa0
sio0: type 16550A
sio0: [FILTER]
sio1 at port 0x2f8-0x2ff irq 3 on isa0
sio1: type 16550A
sio1: [FILTER]
vga0: <Generic ISA VGA> at port 0x3c0-0x3df iomem 0xa0000-0xbffff on isa0
unknown: <PNP0303> can't assign resources (port)
unknown: <PNP0c01> can't assign resources (memory)
unknown: <PNP0c02> can't assign resources (memory)
unknown: <PNP0501> can't assign resources (port)
unknown: <PNP0501> can't assign resources (port)
Timecounter "TSC" frequency 1596009612 Hz quality 800
Timecounters tick every 1.000 msec
ad0: DMA limited to UDMA33, controller found non-ATA66 cable
ad0: 3847MB <ELITE PRO CF CARD 4GB Ver2.21K> at ata0-master UDMA33
GEOM_LABEL: Label for provider ad0s1a is ufsid/4bd1e004dd17db29.
GEOM_LABEL: Label for provider ad0s1d is ufsid/4bd1e0083f1af48a.
GEOM_LABEL: Label for provider ad0s1e is ufsid/4bd1e007d15da553.
Trying to mount root from ufs:/dev/ad0s1a
WARNING: / was not properly dismounted
GEOM_LABEL: Label ufsid/4bd1e004dd17db29 removed.
GEOM_LABEL: Label for provider ad0s1a is ufsid/4bd1e004dd17db29.
GEOM_LABEL: Label ufsid/4bd1e004dd17db29 removed.
GEOM_LABEL: Label ufsid/4bd1e007d15da553 removed.
WARNING: /paul was not properly dismounted
GEOM_LABEL: Label ufsid/4bd1e0083f1af48a removed.
WARNING: /usr was not properly dismounted
re0: link state changed to UP
2:06:13, 2010年5月9日
看起来似乎不是硬件的问题，因为一个cpu占用率在90%以上的死循环运行了3个多小时系统也是正常的。然后把NTPD的版本从FreeBSD 7.2R默认安装的4.2.4p5切换到4.2.6p1，并且配置4个客户端与其同步，并且继续运行死循环测试，3个小时过去了，一切正常。
20:40:54, 2010年5月22日
异常掉电可能引起磁盘分区被标记为dirty，默认地，系统下一次启动时会运行fsck进行分区检查和错误恢复。如果fsck过程中某个操作需要用户干预或确认，而现在的应用没有使用显示器和键盘鼠标，启动过程可能无法继续进行。
1、编辑/etc/fstab，将分区标记为无须检查（dum=0, pass#=0），详见man fstab
2、编辑/etc/rc.conf，添加以下内容：
fsck_y_enable="YES"
fsck_background="NO"
23:02:08,Wednesday, June 09, 2010
已经能够确定散热不良是导致系统不稳定的一个因素。主板配置的存储器工作温度为0~60摄氏度，这样的温度在使用过程中应该是容易达到的，多次模拟测试的结果也是：主板温度达到60摄氏度后就死机了。