root@hxxxxxxx:/var/vdisks# losetup /dev/loop0 vdisk0.img 
/dev/loop0: No such file or directory

root@hxxxxxxx:/var/vdisks# modprobe loop
modprobe: ERROR: ../libkmod/libkmod.c:507 kmod_lookup_alias_from_builtin_file() could not open builtin file '/lib/modules/3.13.0-042stab092.3/modules.builtin.bin'
modprobe: FATAL: Module loop not found.

root@hxxxxxxx:/var/vdisks# ls /lib/modules/3.13.0-042stab092.3/modules.builtin.bin
/lib/modules/3.13.0-042stab092.3/modules.builtin.bin

root@hxxxxxxx:/var/vdisks# uname -a
Linux hxxxxxxx.stratoserver.net 3.13.0-042stab092.3 #1 SMP Sun Jul 20 13:27:24 MSK 2014 x86_64 x86_64 x86_64 GNU/Linux

root@hxxxxxxx:/var/vdisks# cat /etc/lsb-release 
DISTRIB_ID=Ubuntu
DISTRIB_RELEASE=14.04
DISTRIB_CODENAME=trusty
DISTRIB_DESCRIPTION="Ubuntu 14.04.2 LTS"