如果不是CentOS7,可使用此教程升级内核版本(建议直接使用CentOS7)

1 Docker安装

1.1 检查内核版本

[root@root ~]# uname -r 
2.6.32-431.el6.i686

1.2 升级内核版本

1.2.1 导入public key

# 出现错误
[root@root ~]# rpm --import https://www.elrepo.org/RPM-GPG-KEY-elrepo.org
curl: (35) SSL connect error
error: https://www.elrepo.org/RPM-GPG-KEY-elrepo.org: import read failed(2).

# 解决错误
[root@root ~]# yum update nss


# 再次导入,导入成功
[root@root ~]# rpm --import https://www.elrepo.org/RPM-GPG-KEY-elrepo.org

1.3 安装ELRepo

最新的ELRepo地址

# 导入elrepo(建议使用下面的版本)
[root@root ~]# rpm -Uvh https://www.elrepo.org/elrepo-release-6-8.el6.elrepo.noarch.rpm

# 如使用其他版本,安装kernel-lt,出现如下错误(请再次执行上面的一条命令,版本使用文中版本)
[root@root ~]# yum --enablerepo=elrepo-kernel install kernel-lt -y
Loaded plugins: fastestmirror
Error getting repository data for elrepo-kernel, repository not found

1.4 编辑grub.conf文件,修改Grub引导顺序

[root@root ~]# vi /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 (hd0,0)
#          kernel /vmlinuz-version ro root=/dev/mapper/vg_root-lv_root
#          initrd /initrd-[generic-]version.img
#boot=/dev/sda
default=0
timeout=5
splashimage=(hd0,0)/grub/splash.xpm.gz
hiddenmenu

# 刚安装的内核
title CentOS (4.4.207-1.el6.elrepo.i686)
        root (hd0,0)
        kernel /vmlinuz-4.4.207-1.el6.elrepo.i686 ro root=/dev/mapper/vg_root-lv_root rd_NO_LUKS rd_LVM_LV=vg_root/lv_root LANG=en_US.UTF-8 rd_NO_MD SYSFONT=latarcyrheb-sun16 crashkernel=auto rd_LVM_LV=vg_root/lv_swap  KEYBOARDTYPE=pc KEYTABLE=us rd_NO_DM rhgb quiet
        initrd /initramfs-4.4.207-1.el6.elrepo.i686.img

# 原有的内核
title CentOS (2.6.32-431.el6.i686)
        root (hd0,0)
        kernel /vmlinuz-2.6.32-431.el6.i686 ro root=/dev/mapper/vg_root-lv_root rd_NO_LUKS rd_LVM_LV=vg_root/lv_root LANG=en_US.UTF-8 rd_NO_MD SYSFONT=latarcyrheb-sun16 crashkernel=auto rd_LVM_LV=vg_root/lv_swap  KEYBOARDTYPE=pc KEYTABLE=us rd_NO_DM rhgb quiet
        initrd /initramfs-2.6.32-431.el6.i686.img