如何快速的将Centos6.7快速升级3.10.9
参考文档:http://www.xiexianbin.cn/linux/2015/10/15/quickly-upgrade-centos6.5-kernel-from-2.6.32-to-3.10.90/
kernel简介
在yum的ELRepo源中，有mainline（3.13.1）、long-term（3.10.90）这2个内核版本，考虑到long-term更稳定，会长期更新，所以本人推荐选择kernel-lt这个版本。
升级步骤
导入public key
rpm --import https://www.elrepo.org/RPM-GPG-KEY-elrepo.org
安装ELRepo
rpm -ivh http://www.elrepo.org/elrepo-release-6-5.el6.elrepo.noarch.rpm
安装kernel-lt 3.10.90
这里的lt=long-term，这里推荐安装kt，下载地址：http://pan.baidu.com/s/1eQuJkcU。
yum --enablerepo=elrepo-kernel install kernel-lt -y
或者安装kernel-ml，ml=mainline。命令如下：
yum --enablerepo=elrepo-kernel install kernel-ml -y
修改启动引导顺序
修改前：
[root@xiexianbin_cn ~]# vim /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 do not have a /boot partition. This means that # all kernel and initrd paths are relative to /, eg. # root (hd0,0) # kernel /boot/vmlinuz-version ro root=/dev/xvda1 # initrd /boot/initrd-[generic-]version.img #boot=/dev/xvda default=0 timeout=5 splashimage=(hd0,0)/boot/grub/splash.xpm.gz hiddenmenu title CentOS (2.6.32-573.7.1.el6.x86_64) root (hd0,0) kernel /boot/vmlinuz-2.6.32-573.7.1.el6.x86_64 ro root=UUID=94e4e384-0ace-437f-bc96-057dd64f42ee 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 /boot/initramfs-2.6.32-573.7.1.el6.x86_64.img title CentOS (2.6.32-431.23.3.el6.x86_64) root (hd0,0) kernel /boot/vmlinuz-2.6.32-431.23.3.el6.x86_64 ro root=UUID=94e4e384-0ace-437f-bc96-057dd64f42ee 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 /boot/initramfs-2.6.32-431.23.3.el6.x86_64.img
修改后：
[root@xiexianbin_cn ~]# vim /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 do not have a /boot partition. This means that # all kernel and initrd paths are relative to /, eg. # root (hd0,0) # kernel /boot/vmlinuz-version ro root=/dev/xvda1 # initrd /boot/initrd-[generic-]version.img #boot=/dev/xvda default=0 timeout=5 splashimage=(hd0,0)/boot/grub/splash.xpm.gz hiddenmenu title CentOS (3.10.90-1.el6.elrepo.x86_64) root (hd0,0) kernel /boot/vmlinuz-3.10.90-1.el6.elrepo.x86_64 ro root=UUID=94e4e384-0ace-437f-bc96-057dd64f42ee 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 /boot/initramfs-3.10.90-1.el6.elrepo.x86_64.img title CentOS (2.6.32-573.7.1.el6.x86_64) root (hd0,0) kernel /boot/vmlinuz-2.6.32-573.7.1.el6.x86_64 ro root=UUID=94e4e384-0ace-437f-bc96-057dd64f42ee 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 /boot/initramfs-2.6.32-573.7.1.el6.x86_64.img title CentOS (2.6.32-431.23.3.el6.x86_64) root (hd0,0) kernel /boot/vmlinuz-2.6.32-431.23.3.el6.x86_64 ro root=UUID=94e4e384-0ace-437f-bc96-057dd64f42ee 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 /boot/initramfs-2.6.32-431.23.3.el6.x86_64.img
修改前，前确认新安装安装内核的位置，然后设置default值（从0开始），一般新安装的内核在第一个位置，所以设置default=0。
重启生效
升级前kernel版本：
[root@xiexianbin_cn ~]# uname -a Linux xiexianbin_cn 2.6.32-573.7.1.el6.x86_64 #1 SMP Tue Sep 22 22:00:00 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux
升级后kernel版本：
[root@xiexianbin_cn ~]# uname -a Linux xiexianbin_cn 3.10.90-1.el6.elrepo.x86_64 #1 SMP Thu Oct 1 15:15:53 EDT 2015 x86_64 x86_64 x86_64 GNU/Linux
更多内核下载地址
可能存在的问题
遇到CentOs内核升级后，启动无法指定系统内核。原因是/etc/grub.conf和/boot/grub/grub.conf（为准）信息不同步导致。
cp -rf /boot/grub/grub.conf /etc/grub.conf
完毕。
