阿里云上的6.5CentOS模版还是2.6的内核,对Docker来说就有些低版本了(Docker推荐3.8 :)),于是着手升级

lsb_release -a
LSB Version:	:base-4.0-amd64:base-4.0-noarch:core-4.0-amd64:core-4.0-noarch
Distributor ID:	CentOS
Description:	CentOS release 6.5 (Final)
Release:	6.5
Codename:	Final

uname -a
Linux iZ289l79vfqZ 2.6.32-431.23.3.el6.x86_64 #1 SMP Thu Jul 31 17:20:51 UTC 2014 x86_64 x86_64 x86_64 GNU/Linux

为了配合Docker,使用YUM中的long-term 源升级

rpm --import https://www.elrepo.org/RPM-GPG-KEY-elrepo.org
yum --enablerepo=elrepo-kernel install kernel-lt -y

升级完成后,修改启动内核,修改default=0 (新安装的内核在第一个)

default=0
timeout=5
splashimage=(hd0,0)/boot/grub/splash.xpm.gz
hiddenmenu
title CentOS (3.10.63-1.el6.elrepo.x86_64)
        root (hd0,0)
        kernel /boot/vmlinuz-3.10.63-1.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-3.10.63-1.el6.elrepo.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

重启,然后uname -a 查看。