カーネルダンプ(kdump)のインストール

今更ですが、RHEL5環境にkdumpをインストールしました。
なお、適用にはOSの再起動が必須なので、運用中のサーバにインストールする場合は注意が必要です。

1.kexec-toolsのインストール

# yum install kexec-tools
～～～中略～～～
Dependencies Resolved

================================================================================================================================
 Package                        Arch                    Version                                   Repository               Size
================================================================================================================================
Installing:
 kexec-tools                    i386                    1.102pre-164.el5                          base                    580 k
Installing for dependencies:
 busybox                        i386                    1:1.2.0-14.el5.centos                     base                    1.1 M

Transaction Summary
================================================================================================================================
Install       2 Package(s)
Upgrade       0 Package(s)

Total download size: 1.6 M

～～～下略～～～

なお、これだけではkdumpを起動しようとしてもエラーがでて起動すらしません。

# /etc/rc.d/init.d/kdump start
Detected change(s) the following file(s):
  
  /etc/kdump.conf
Rebuilding /boot/initrd-2.6.18-371.1.2.el5kdump.img
Starting kdump:[失敗]

# /etc/rc.d/init.d/kdump status
Kdump is not operational

# cat /var/log/messages
～～～上略～～～
Apr 12 1:00:10 HOGE kdump: No crashkernel parameter was specified or crashkernel memory reservation failed
Apr 12 1:00:10 HOGE kdump: failed to start up

2.grub.confの設定
kdump用にメモリの割り当てを設定します

# vi /etc/grub.conf
# grub.conf generated by anaconda
#
# Note that you do not have to rerun grub after making changes to this file
# NOTICE:  You have a /boot partition.  This means that
#          all kernel and initrd paths are relative to /boot/, eg.
#          root (hd0,0)
#          kernel /vmlinuz-version ro root=/dev/VolGroup00/LogVol00
#          initrd /initrd-version.img
#boot=/dev/sda
default=0
timeout=5
splashimage=(hd0,0)/grub/splash.xpm.gz
hiddenmenu
title Red Hat Enterprise Linux Server (2.6.18-371.1.2.el5)
        root (hd0,0)
　　　　　　※赤文字の部分を追記します。なお、RHEL6の場合は@以降は不要(Auto)です
        kernel /vmlinuz-2.6.18-371.1.2.el5 ro root=/dev/VolGroup00/LogVol00 rhgb quiet crashkernel=128M@16M
        initrd /initrd-2.6.18-371.1.2.el5.img

3.OSの再起動
設定を適用するためにOSを再起動します。

4.OS再起動後の動作確認

# /etc/rc.d/init.d/kdump status
Kdump is operational

# cat /var/log/messages
～～～上略～～～
Apr 12 1:02:10 HOGE kdump: kexec: loaded kdump kernel
Apr 12 1:02:10 HOGE kdump: started up