diagnosing a reacurring system freeze

Zbigniew Szalbot zbyszek at szalbot.homedns.org
Thu Feb 15 22:29:37 UTC 2007


Hello,

Derek Ragona wrote:
> First you should provide more information such as the output from your
> dmesg, whether you have the server running X or just text mode.

In my case I do not run X, the system mostly operates mysql database and
exim MTA (and this causes a bigger load sometimes up to 3.0 or so).

>
> Describe your lockup, does the system completely freeze, or is it still
> ping-able?
In my case it is always a complete freeze but only for a relatively short
period of time (20-30 seconds, sometimes longer though - up to 2 minutes).

For example, I noticed on a few occasions that when I used cat |grep on a
log file and the output displayed on screen was quite extensive (lots of
data), the system would freeze. But not always.

Here's the dmesg.today output:

Copyright (c) 1992-2007 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 6.2-RELEASE #0: Mon Jan 22 12:52:41 CET 2007
    root at 192.168.11.51:/usr/obj/usr/src/sys/LISTS
Timecounter "i8254" frequency 1193182 Hz quality 0
CPU: Intel Pentium III (868.20-MHz 686-class CPU)
  Origin = "GenuineIntel"  Id = 0x686  Stepping = 6
  Features=0x387f9ff<FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,SEP,MTRR,PGE,MCA,CMOV,PAT,PSE36,PN,MMX,FXSR,SSE>
real memory  = 535691264 (510 MB)
avail memory = 514801664 (490 MB)
kbd1 at kbdmux0
acpi0: <MEIP01 > on motherboard
acpi0: Power Button (fixed)
Timecounter "ACPI-fast" frequency 3579545 Hz quality 1000
acpi_timer0: <24-bit timer at 3.579545MHz> port 0x408-0x40b on acpi0
cpu0: <ACPI CPU> on acpi0
acpi_button0: <Power Button> on acpi0
pcib0: <ACPI Host-PCI bridge> port 0xcf8-0xcff on acpi0
pci0: <ACPI PCI bus> on pcib0
agp0: <Intel 82810E (i810E GMCH) SVGA controller> mem
0xe8000000-0xebffffff,0xeff80000-0xefffffff irq 10 at device 1.0 on pci0
pcib1: <ACPI PCI-PCI bridge> at device 30.0 on pci0
pci1: <ACPI PCI bus> on pcib1
dc0: <Davicom DM9102A 10/100BaseTX> port 0xbc00-0xbcff mem
0xefdfff00-0xefdfffff irq 11 at device 0.0 on pci1
miibus0: <MII bus> on dc0
ukphy0: <Generic IEEE 802.3u media interface> on miibus0
ukphy0:  10baseT, 10baseT-FDX, 100baseTX, 100baseTX-FDX, auto
dc0: Ethernet address: 00:80:ad:82:6e:58
isab0: <PCI-ISA bridge> at device 31.0 on pci0
isa0: <ISA bus> on isab0
atapci0: <Intel ICH UDMA66 controller> port
0x1f0-0x1f7,0x3f6,0x170-0x177,0x376,0xffa0-0xffaf at device 31.1 on pci0
ata0: <ATA channel 0> on atapci0
ata1: <ATA channel 1> on atapci0
pci0: <serial bus, USB> at device 31.2 (no driver attached)
pci0: <serial bus, SMBus> at device 31.3 (no driver attached)
pci0: <multimedia, audio> at device 31.5 (no driver attached)
atkbdc0: <Keyboard controller (i8042)> port 0x60,0x64 irq 1 on acpi0
atkbd0: <AT Keyboard> irq 1 on atkbdc0
kbd0 at atkbd0
atkbd0: [GIANT-LOCKED]
fdc0: <floppy drive controller> port 0x3f0-0x3f3,0x3f4-0x3f5,0x3f7 irq 6
drq 2 on acpi0
fdc0: [FAST]
fd0: <1440-KB 3.5" drive> on fdc0 drive 0
sio0: <16550A-compatible COM port> port 0x3f8-0x3ff irq 4 flags 0x10 on acpi0
sio0: type 16550A
ppc0: <ECP parallel printer port> port 0x378-0x37f,0x778-0x77b irq 7 drq 3
on acpi0
ppc0: SMC-like chipset (ECP/EPP/PS2/NIBBLE) in COMPATIBLE mode
ppc0: FIFO with 16/16/9 bytes threshold
ppbus0: <Parallel port bus> on ppc0
plip0: <PLIP network interface> on ppbus0
lpt0: <Printer> on ppbus0
lpt0: Interrupt-driven port
ppi0: <Parallel I/O> on ppbus0
pmtimer0 on isa0
orm0: <ISA Option ROM> at iomem 0xc0000-0xcbfff on isa0
sc0: <System console> at flags 0x100 on isa0
sc0: VGA <16 virtual consoles, flags=0x300>
sio1: configured irq 3 not in bitmap of probed irqs 0
sio1: port may not be enabled
vga0: <Generic ISA VGA> at port 0x3c0-0x3df iomem 0xa0000-0xbffff on isa0
Timecounter "TSC" frequency 868204315 Hz quality 800
Timecounters tick every 1.000 msec
ad0: 76319MB <WDC WD800JB-00JJC0 05.01C05> at ata0-master UDMA66
acd0: CDROM <LTN485/KQG1> at ata0-slave PIO4
Trying to mount root from ufs:/dev/ad0s1a
dc0: watchdog timeout
dc0: watchdog timeout
dc0: watchdog timeout
dc0: watchdog timeout
dc0: watchdog timeout
dc0: watchdog timeout
dc0: watchdog timeout
dc0: watchdog timeout
dc0: watchdog timeout
dc0: watchdog timeout
dc0: watchdog timeout
dc0: watchdog timeout
dc0: watchdog timeout
dc0: watchdog timeout
dc0: watchdog timeout
dc0: watchdog timeout
dc0: watchdog timeout
dc0: watchdog timeout
dc0: watchdog timeout
dc0: watchdog timeout
dc0: watchdog timeout
dc0: watchdog timeout
dc0: watchdog timeout
dc0: watchdog timeout
dc0: watchdog timeout
dc0: watchdog timeout
dc0: watchdog timeout
dc0: watchdog timeout
dc0: watchdog timeout
dc0: watchdog timeout
dc0: watchdog timeout
dc0: watchdog timeout
dc0: watchdog timeout
dc0: watchdog timeout
dc0: watchdog timeout
dc0: watchdog timeout
dc0: watchdog timeout
dc0: watchdog timeout
dc0: watchdog timeout
dc0: watchdog timeout
dc0: watchdog timeout
dc0: watchdog timeout
dc0: watchdog timeout
dc0: watchdog timeout
dc0: watchdog timeout
dc0: watchdog timeout
dc0: watchdog timeout
dc0: watchdog timeout
dc0: watchdog timeout
dc0: watchdog timeout
swap_pager: out of swap space
swap_pager_getswapspace(1): failed
swap_pager_getswapspace(15): failed
swap_pager_getswapspace(7): failed
swap_pager: out of swap space
swap_pager_getswapspace(6): failed
pid 85217 (mysqld), uid 88, was killed: out of swap space
dc0: watchdog timeout
dc0: watchdog timeout
dc0: watchdog timeout
dc0: watchdog timeout
dc0: watchdog timeout
dc0: watchdog timeout
dc0: watchdog timeout
dc0: watchdog timeout
dc0: watchdog timeout
dc0: watchdog timeout
dc0: watchdog timeout
dc0: watchdog timeout
dc0: watchdog timeout
dc0: watchdog timeout
dc0: watchdog timeout
dc0: watchdog timeout
dc0: watchdog timeout
dc0: watchdog timeout

The instance where mysql was killed did not happen today but a few days
ago, when there was an excessive load on the box. I failed to implement
some precautions and as a result the load went above 10.

Thanks for any further hints. I get 1, 2 such freezes a day.

-- 
Zbigniew Szalbot



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