字符文件丢失处理

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From   Fri Apr 30 16:01:02 2010
Date: Fri, 30 Apr 2010 16:01:02 +0800
From: (Cron Daemon)
To:
Subject: Cron <> run-parts /etc/cron.hourly
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/etc/cron.hourly/mcelog.cron:

mcelog: Cannot open /dev/mem for DMI decoding: No such file or directory

 

字符文件/dev/mem丢失了。

处理方法：

1、查到/dev/mem的主次设备号

#cat /proc/devices |grep -3 mem

Character devices:
  1 mem
  4 /dev/vc/0
  4 tty
  4 ttyS

2、从别的机器看到/dev/mem的权限

#ll /dev/mem

crw-r----- 1 root kmem 1, 1 03-12 23:03 /dev/mem

3、创建字符设备

# mknod -m 640 /dev/mem c 1 1

# ll /dev/mem
crw-r----- 1 root root 1, 1 04-30 18:26 /dev/mem

4、验证

#rm -f /dev/mem

#cat /etc/cron.hourly/mcelog.cron

#!/bin/bash

if [ -e /proc/xen ] && [ `cat /sys/hypervisor/uuid` != "00000000-0000-0000-0000-000000000000" ]; then
        # this is a PV Xen guest.  Do not run mcelog.
        exit 1;
else
        /usr/sbin/mcelog --ignorenodev --filter >> /var/log/mcelog
fi

#/usr/sbin/mcelog --ignorenodev --filter >> /var/log/mcelog
mcelog: Cannot open /dev/mem for DMI decoding: No such file or directory

#mknod -m 640 /dev/mem c 1 1

#/usr/sbin/mcelog --ignorenodev --filter >> /var/log/mcelog
返回成功。