CentOS升级内核的方法

升级前的内核版本为：2.6.32-431.el6.x86_64

升级后的内核版本为：3.10.101-1.el6.elrepo.x86_64

升级方法：

1.导入key

rpm --import https://www.elrepo.org/RPM-GPG-KEY-elrepo.org

2.安装elrepo的yum源

rpm -ivh http://www.elrepo.org/elrepo-release-6-5.el6.elrepo.noarch.rpm

3.安装内核

yum --enablerepo=elrepo-kernel install kernel-lt -y

4.修改启动顺序

vi /etc/grub.conf

　　看到grub.conf内容如下：

# 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/sda2
#          initrd /initrd-[generic-]version.img
#boot=/dev/sda
default=1
timeout=5
splashimage=(hd0,0)/grub/splash.xpm.gz
hiddenmenu
title CentOS (3.10.101-1.el6.elrepo.x86_64)
	root (hd0,0)
	kernel /vmlinuz-3.10.101-1.el6.elrepo.x86_64 ro root=UUID=7cb8b8e8-898e-4980-82e3-6f590b2a2145 rd_NO_LUKS rd_NO_LVM LANG=en_US.UTF-8 rd_NO_MD SYSFONT=latarcyrheb-sun16 crashkernel=auto  KEYBOARDTYPE=pc KEYTABLE=us rd_NO_DM rhgb quiet
	initrd /initramfs-3.10.101-1.el6.elrepo.x86_64.img
title CentOS (2.6.32-431.el6.x86_64)
	root (hd0,0)
	kernel /vmlinuz-2.6.32-431.el6.x86_64 ro root=UUID=7cb8b8e8-898e-4980-82e3-6f590b2a2145 rd_NO_LUKS rd_NO_LVM LANG=en_US.UTF-8 rd_NO_MD SYSFONT=latarcyrheb-sun16 crashkernel=auto  KEYBOARDTYPE=pc KEYTABLE=us rd_NO_DM rhgb quiet
	initrd /initramfs-2.6.32-431.el6.x86_64.img

从配置文件看出：系统中安装有两个内核，分别是 CentOS (3.10.101-1.el6.elrepo.x86_64) 和 CentOS (2.6.32-431.el6.x86_64)

default=1表示启动第二个内核，既：CentOS (2.6.32-431.el6.x86_64)

修改default=1为default=0，既启动第一个内核：CentOS (3.10.101-1.el6.elrepo.x86_64)

5，重启系统

reboot

6，查看内核版本

uname -r

　　此时内核版本为：3.10.101-1.el6.elrepo.x86_64