##记得切换到root用户执行升级操作.

[root@localhost ~]# uname -a   ##旧版

Linux localhost.localdomain 2.6.32-279.el6.i686 #1 SMP Fri Jun 22 10:59:55 UTC 2012 i686 i686 i386 GNU/Linux

[root@localhost ~]# rpm --import https://www.elrepo.org/RPM-GPG-KEY-elrepo.org

[root@localhost ~]# rpm -ivh https://www.elrepo.org/elrepo-release-6-8.el6.elrepo.noarch.rpm

[root@localhost ~]# yum --enablerepo=elrepo-kernel install kernel-lt -y  ##此步会有点慢

[root@localhost ~]# vim /etc/grub.conf default=1 改为 default=0  ##设置默认以3.10核心启动，默认是按照旧的核心启动

[root@localhost ~]# reboot

[root@localhost ~]# uname -a  ##升级后的版本

Linux localhost.localdomain 3.10.104-1.el6.elrepo.i686 #1 SMP Fri Oct 21 09:11:59 EDT 2016 i686 i686 i386 GNU/Linux

[root@localhost ~]# cat /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,)

# kernel /vmlinuz-version ro root=/dev/sda2

# initrd /initrd-[generic-]version.img

#boot=/dev/sda

default=

timeout=

splashimage=(hd0,)/grub/splash.xpm.gz

hiddenmenu

title CentOS (3.10.-.el6.x86_64)

 root (hd0,)

 kernel /vmlinuz-3.10.-.el6.x86_64 ro root=UUID=--472c-8ca4-110fb82e9959 rd_NO_LUKS rd_NO_LVM LANG=en_US.UTF- rd_NO_MD SYSFONT=latarcyrheb-sun16 crashkernel=auto KEYBOARDTYPE=pc KEYTABLE=us rd_NO_DM rhgb quiet

 initrd /initramfs-3.10.-.el6.x86_64.img

title CentOS (2.6.-.el6.x86_64)

 root (hd0,)

 kernel /vmlinuz-2.6.-.el6.x86_64 ro root=UUID=--472c-8ca4-110fb82e9959 rd_NO_LUKS rd_NO_LVM LANG=en_US.UTF- rd_NO_MD SYSFONT=latarcyrheb-sun16 crashkernel=auto KEYBOARDTYPE=pc KEYTABLE=us rd_NO_DM rhgb quiet

 initrd /initramfs-2.6.-.el6.x86_64.img

cd /etc/yum.repos.d

wget http://www.hop5.in/yum/el6/hop5.repo

yum install kernel-ml-aufs kernel-ml-aufs-devel -y