[libvirt-users] virsh start failed (Failed to query file context on ...)

hi all, I try to follow the instructions in http://libvirt.org/drvlxc.html to config libvirt-lxc, but failed when starting the lxc. The domain config file: # cat b.xml <domain type='lxc'> <name>b</name> <memory>32768</memory> <os> <type>exe</type> <init>/bin/sh</init> </os> <vcpu>1</vcpu> <clock offset='utc'/> <on_poweroff>destroy</on_poweroff> <on_reboot>restart</on_reboot> <on_crash>destroy</on_crash> <devices> <emulator>/usr/libexec/libvirt_lxc</emulator> <filesystem type='mount'> <source dir='/data/lxc/centos6'/> <target dir='/'/> </filesystem> <interface type='network'> <source network='default'/> </interface> <console type='pty' /> </devices> </domain> then define it: # virsh --connect lxc:/// define b.xml Domain b defined from b.xml then start: # virsh --connect lxc:/// start b error: Failed to start domain b error: internal error guest failed to start: 2012-10-10 09:56:17.369+0000: 452722: info : libvirt version: 0.9.10, package: 21.el6_3.4 (CentOS BuildSystem <http://bugs.centos.org>;, 2012-08-23-18:28:26, c6b9.bsys.dev.centos.org) 2012-10-10 09:56:17.369+0000: 452722: error : lxcControllerRun:1484 : Failed to query file context on /data/lxc/centos6: No data available It's the filesystem mount section that cause this problem. The tutorial says the path '/data/lxc/centos6' should be "private root filesystem (perhaps hand-crafted using busybox, or installed from media, debootstrap, whatever)", but I am not quite clear about what this path should be. In my case, the "/data/lxc/centos6" is the root of template downloaded from http://wiki.openvz.org/Download/template/precreated. # pwd /data/lxc/centos6 # ls bin boot dev etc fastboot home lib media mnt opt proc root sbin selinux srv sys tmp usr var Can someone elaborate what should <source dir='/data/lxc/centos6'/> be? many thanks