linux的内核升级频繁，当做好系统后，象ubuntu那类发行版因自动升级后容易造成部分软件或功能不能正常的工作，这时我往往需要使用原来的kernel：
/boot/grub/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/hda2
# initrd /initrd-version.img
#boot=/dev/hda
default=0
timeout=5
splashimage=(hd0,0)/grub/splash.xpm.gz
hiddenmenu
title linux (xxxxxxx)
root (hd0,0)
kernel /vmlinuz-xxxxxx ro root=LABEL=/ rhgb quiet
initrd /initrd-xxxxxxx.img
title linux (xxxxxxxx)
root (hd0,0)
kernel /vmlinuz-xxxxxx ro root=LABEL=/ rhgb quiet
initrd /initrd-xxxxxxx.img
修改成相应的配置文件即可。
