crash utility help page:  log


NAME
  log - dump system message buffer

SYNOPSIS
  log [-tdm]

DESCRIPTION
  This command dumps the kernel log_buf contents in chronological order.  The
  command supports the older log_buf formats, which may or may not contain a
  timestamp inserted prior to each message, as well as the newer variable-length
  record format, where the timestamp is contained in each log entry's header.
  
    -t  Display the message text without the timestamp; only applicable to the
        variable-length record format.
    -d  Display the dictionary of key/value pair properties that are optionally
        appended to a message by the kernel's dev_printk() function; only
        applicable to the variable-length record format.
    -m  Display the message log level in brackets preceding each message.  For
        the variable-length record format, the level will be displayed in 
        hexadecimal, and depending upon the kernel version, also contains the
        facility or flags bits.
 

EXAMPLES
  Dump the kernel message buffer:

    crash> log
    Linux version 2.2.5-15smp (root@mclinux1) (gcc version egcs-2.91.66 19990
    314/Linux (egcs-1.1.2 release)) #1 SMP Thu Aug 26 11:04:37 EDT 1999
    Intel MultiProcessor Specification v1.4
        Virtual Wire compatibility mode.
    OEM ID: DELL     Product ID: WS 410       APIC at: 0xFEE00000
    Processor #0 Pentium(tm) Pro APIC version 17
    Processor #1 Pentium(tm) Pro APIC version 17
    I/O APIC #2 Version 17 at 0xFEC00000.
    Processors: 2
    mapped APIC to ffffe000 (fee00000)
    mapped IOAPIC to ffffd000 (fec00000)
    Detected 447696347 Hz processor.
    Console: colour VGA+ 80x25
    Calibrating delay loop... 445.64 BogoMIPS
    ...
      8K byte-wide RAM 5:3 Rx:Tx split, autoselect/Autonegotiate interface.
      MII transceiver found at address 24, status 782d.
      Enabling bus-master transmits and whole-frame receives.
    Installing knfsd (copyright (C) 1996 okir@monad.swb.de).
    nfsd_init: initialized fhcache, entries=256
    ...
 
  Do the same thing, but also show the log level preceding each message:

    crash> log -m
    <4>Linux version 2.2.5-15smp (root@mclinux1) (gcc version egcs-2.91.66 19990
    314/Linux (egcs-1.1.2 release)) #1 SMP Thu Aug 26 11:04:37 EDT 1999
    <4>Intel MultiProcessor Specification v1.4
    <4>    Virtual Wire compatibility mode.
    <4>OEM ID: DELL     Product ID: WS 410       APIC at: 0xFEE00000
    <4>Processor #0 Pentium(tm) Pro APIC version 17
    <4>Processor #1 Pentium(tm) Pro APIC version 17
    <4>I/O APIC #2 Version 17 at 0xFEC00000.
    <4>Processors: 2
    <4>mapped APIC to ffffe000 (fee00000)
    <4>mapped IOAPIC to ffffd000 (fec00000)
    <4>Detected 447696347 Hz processor.
    <4>Console: colour VGA+ 80x25
    <4>Calibrating delay loop... 445.64 BogoMIPS
    ...
    <6>  8K byte-wide RAM 5:3 Rx:Tx split, autoselect/Autonegotiate interface.
    <6>  MII transceiver found at address 24, status 782d.
    <6>  Enabling bus-master transmits and whole-frame receives.
    <6>Installing knfsd (copyright (C) 1996 okir@monad.swb.de).
    <7>nfsd_init: initialized fhcache, entries=256
    ... 
 
  On a system with the variable-length record format, and whose log_buf has been
  filled and wrapped around, display the log with timestamp data:

    crash> log
    [    0.467730] pci 0000:ff:02.0: [8086:2c10] type 00 class 0x060000
    [    0.467749] pci 0000:ff:02.1: [8086:2c11] type 00 class 0x060000
    [    0.467769] pci 0000:ff:02.4: [8086:2c14] type 00 class 0x060000
    [    0.467788] pci 0000:ff:02.5: [8086:2c15] type 00 class 0x060000
    [    0.467809] pci 0000:ff:03.0: [8086:2c18] type 00 class 0x060000
    [    0.467828] pci 0000:ff:03.1: [8086:2c19] type 00 class 0x060000
    ...
 
  Display the same message text as above, without the timestamp data:

    crash> log -t
    pci 0000:ff:02.0: [8086:2c10] type 00 class 0x060000
    pci 0000:ff:02.1: [8086:2c11] type 00 class 0x060000
    pci 0000:ff:02.4: [8086:2c14] type 00 class 0x060000
    pci 0000:ff:02.5: [8086:2c15] type 00 class 0x060000
    pci 0000:ff:03.0: [8086:2c18] type 00 class 0x060000
    pci 0000:ff:03.1: [8086:2c19] type 00 class 0x060000
    ...
 
  Display the same message text as above, with appended dictionary data:

    crash> log -td
    pci 0000:ff:02.0: [8086:2c10] type 00 class 0x060000
    SUBSYSTEM=pci
    DEVICE=+pci:0000:ff:02.0
    pci 0000:ff:02.1: [8086:2c11] type 00 class 0x060000
    SUBSYSTEM=pci
    DEVICE=+pci:0000:ff:02.1
    pci 0000:ff:02.4: [8086:2c14] type 00 class 0x060000
    SUBSYSTEM=pci
    DEVICE=+pci:0000:ff:02.4
    pci 0000:ff:02.5: [8086:2c15] type 00 class 0x060000
    SUBSYSTEM=pci
    DEVICE=+pci:0000:ff:02.5
    pci 0000:ff:03.0: [8086:2c18] type 00 class 0x060000
    SUBSYSTEM=pci
    DEVICE=+pci:0000:ff:03.0
    pci 0000:ff:03.1: [8086:2c19] type 00 class 0x060000
    SUBSYSTEM=pci
    DEVICE=+pci:0000:ff:03.1
    ...