Centos 5.5文件系统使用的是ext3，服务器死机后重启出现无法正常启动，控制台显示文件系统有问题，输入密码后登录单用户显示文件系统只读，查看日志显示：
kernel: EXT3-fs warning (device sda5): dx_probe: Unrecognised inode hash code 32
kernel: EXT3-fs warning (device sda5): dx_probe: Corrupt dir inode 7660045, running e2fsck is recommended.
kernel: EXT3-fs error (device sda5): ext3_lookup: unlinked inode 7661556 in dir #7660045
kernel: Aborting journal on device sda5.
kernel: EXT3-fs error (device sda5): ext3_lookup: unlinked inode 7661557 in dir #7660045
kernel: EXT3-fs error (device sda5): ext3_lookup: unlinked inode 7661563 in dir #7660045
Sep 1 01:34:08 localhost kernel: EXT3-fs error (device sda5): ext3_lookup: unlinked inode 7661575 in dir #7660045
kernel: EXT3-fs error (device sda5): ext3_lookup: unlinked inode 7661614 in dir #7660045
kernel: EXT3-fs error (device sda5): ext3_lookup: unlinked inode 7661627 in dir #7660045
kernel: EXT3-fs error (device sda5): ext3_lookup: unlinked inode 7661629 in dir #7660045
kernel: EXT3-fs error (device sda5): ext3_lookup: unlinked inode 7661639 in dir #7660045
kernel: EXT3-fs error (device sda5): ext3_lookup: unlinked inode 7661675 in dir #7660045
kernel: EXT3-fs error (device sda5): ext3_lookup: unlinked inode 7661690 in dir #7660045
解决办法：
umount /dev/sda5
e2fsck -y /dev/sda5
如果以上方法在umount的时候出现磁盘is busy的情况，要用
fuser -km /dev/sdg1 杀掉占用的进程，之后就可以umount了，磁盘修复要等待一段时间
如果不能卸载，重启进入单用户模式操作。