Hello, It's not possible to start LXC container inside user namespace with root filesystem on loop device, because it tries to mount root FS from container's user namespace (lxcContainerSetupPivotRoot) and gets EPERM: 2015-03-19 12:48:18.545+0000: 1: debug : lxcContainerChild:2278 : Tearing down container Failed to mount device /dev/loop0 to /var/run/libvirt/lxc/instance-0000000b.root: Operation not permitted So I wonder, if someone tried to run LXC container with such configuration with success. Here is my config: <domain type='lxc'> <name>instance-0000000b</name> <uuid>d918c415-0a00-4c12-896e-19e4711111d3</uuid> <memory unit='KiB'>524288</memory> <currentMemory unit='KiB'>524288</currentMemory> <cputune> <shares>1024</shares> </cputune> <os> <type arch='x86_64'>exe</type> <init>/sbin/init</init> <cmdline>console=tty0 console=ttyS0</cmdline> </os> <idmap> <uid start='0' target='10000' count='1000'/> <gid start='0' target='10000' count='1000'/> </idmap> <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='file' accessmode='passthrough'> <driver type='loop' format='raw'/> <source file='/root/2.img'/> <target dir='/'/> </filesystem> <console type='pty'> <target type='lxc' port='0'/> </console> </devices> </domain> -- Dmitry Guryanov