转自https://www.linuxidc.com/Linux/2014-10/107891.htm
一.问题描述：
KVM中宿主机通过console无法连接客户机，卡在这里不动了。
# virsh console vm01
Connected to domain vm01
Escape character is ^]
为KVM客户机添加virsh console支持 http://www.linuxidc.com/Linux/2013-02/79556.htm
二、解决办法：利用vnc或宿主机的桌面进入客户机vm01中添加参数
1、添加ttyS0的安全许可，允许root登录:
# echo "ttyS0" >> /etc/securetty
2、在/etc/grub.conf文件中为内核添加参数:
console=ttyS0
这步要注意：
console=ttyS0一定要放在kernel这行中(大约在第16行)，不能单独一行，即console=ttyS0是kernel的一个参数，不是单独的，如下（往右拉进度条，在最后）：
# cat -n /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/VolGroup-lv_root
# initrd /initrd-[generic-]version.img
#boot=/dev/vda
default=0
timeout=5
splashimage=(hd0,0)/grub/splash.xpm.gz
hiddenmenu
title Red Hat Enterprise Linux (2.6.32-431.el6.x86_64)
root (hd0,0)
kernel /vmlinuz-2.6.32-431.el6.x86_64 ro root=/dev/mapper/VolGroup-lv_root rd_NO_LUKS LANG=en_US.UTF-8 rd_NO_MD rd_LVM_LV=VolGroup/lv_swap SYSFONT=latarcyrheb-sun16 crashkernel=auto rd_LVM_LV=VolGroup/lv_root KEYBOARDTYPE=pc KEYTABLE=us rd_NO_DM rhgb quiet console=ttyS0
initrd /initramfs-2.6.32-431.el6.x86_64.img
3、在/etc/inittab中添加agetty:
S0:12345:respawn:/sbin/agetty ttyS0 115200
4、重启客户机:
# reboot
三、问题解决
# virsh console vm01
Connected to domain vm01
Escape character is ^]
Red Hat Enterprise Linux Server release 6.5 (Santiago)
Kernel 2.6.32-431.el6.x86_64 on an x86_64
vm01 login: root
Password:
Last login: Sun Oct 12 00:11:47 on tty1
[root@vm01 ~]#