Oracle Linux 6.4 に crash をインストールする

Oracle Linux 6.4 で動的にカーネルの動作を追跡するために crash をインストールした。

crash とは

crashユーティリティを使用すると、実行中のOracle Linuxシステム、またはカーネル・クラッシュの結果であるコア・ダンプの状態を分析できます。crashは、ソース・コード・デバッグ機能を提供するためにGNUデバッガgdbとマージされています。

10.2 crashデバッガの使用

インストール手順

# yum install crash
# export DLP="https://oss.oracle.com/ol6/debuginfo"
# wget ${DLP}/kernel-uek-debuginfo-`uname -r`.rpm
# wget ${DLP}/kernel-uek-debuginfo-common-`uname -r`.rpm
# rpm -Uvh kernel-uek-debuginfo-2.6.39-400.17.1.el6uek.x86_64.rpm kernel-uek-debuginfo-common-2.6.39-400.17.1.el6uek.x86_64.rpm 

使ってみる

  • 起動する
# crash
crash 6.1.0-1.0.1.el6
Copyright (C) 2002-2012  Red Hat, Inc.
Copyright (C) 2004, 2005, 2006, 2010  IBM Corporation
Copyright (C) 1999-2006  Hewlett-Packard Co
Copyright (C) 2005, 2006, 2011, 2012  Fujitsu Limited
Copyright (C) 2006, 2007  VA Linux Systems Japan K.K.
Copyright (C) 2005, 2011  NEC Corporation
Copyright (C) 1999, 2002, 2007  Silicon Graphics, Inc.
Copyright (C) 1999, 2000, 2001, 2002  Mission Critical Linux, Inc.
This program 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.  Enter "help copying" to see the conditions.
This program has absolutely no warranty.  Enter "help warranty" for details.
 
GNU gdb (GDB) 7.3.1
Copyright (C) 2011 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.  Type "show copying"
and "show warranty" for details.
This GDB was configured as "x86_64-unknown-linux-gnu"...

crash: read error: kernel virtual address: ffffffff8152f460  type: "cpu_possible_mask"

crash: this kernel may be configured with CONFIG_STRICT_DEVMEM, which
       renders /dev/mem unusable as a live memory source.

crash: trying /proc/kcore as an alternative to /dev/mem

      KERNEL: /usr/lib/debug/lib/modules/2.6.39-400.17.1.el6uek.x86_64/vmlinux
    DUMPFILE: /proc/kcore
        CPUS: 4
        DATE: Thu Feb 20 21:41:05 2014
      UPTIME: 00:32:46
LOAD AVERAGE: 0.84, 0.76, 0.69
       TASKS: 390
    NODENAME: yazekats-linux
     RELEASE: 2.6.39-400.17.1.el6uek.x86_64
     VERSION: #1 SMP Fri Feb 22 18:16:18 PST 2013
     MACHINE: x86_64  (2593 Mhz)
      MEMORY: 15.7 GB
         PID: 20470
     COMMAND: "crash"
        TASK: ffff8803dba62180  [THREAD_INFO: ffff8803956cc000]
         CPU: 0
       STATE: TASK_RUNNING (ACTIVE)

crash> 
  • メモリ情報を見てみる
crash> kmem -i
              PAGES        TOTAL      PERCENTAGE
 TOTAL MEM  4039636      15.4 GB         ----
      FREE  2826719      10.8 GB   69% of TOTAL MEM
      USED  1212917       4.6 GB   30% of TOTAL MEM
    SHARED   729843       2.8 GB   18% of TOTAL MEM
   BUFFERS    29494     115.2 MB    0% of TOTAL MEM
    CACHED   890931       3.4 GB   22% of TOTAL MEM
      SLAB    57404     224.2 MB    1% of TOTAL MEM

TOTAL SWAP  2021375       7.7 GB         ----
 SWAP USED        0            0    0% of TOTAL SWAP
 SWAP FREE  2021375       7.7 GB  100% of TOTAL SWAP