to the point, maybe your supermin appliance should have its own kernel? or bug ubuntu devs to make the kernel world readable. more detail, as requested Trying to build an image of ubuntu. exact command virt-builder ubuntu-14.04 exact output, $ virt-builder ubuntu-14.04 [ 0.0] Downloading: http://libguestfs.org/download/builder/ubuntu-14.04.xz [ 1.0] Creating disk image: ubuntu-14.04.img [ 1.0] Uncompressing: http://libguestfs.org/download/builder/ubuntu-14.04.xz [ 22.0] Running virt-resize to expand the disk to 4.2G libguestfs: trace: set_verbose true libguestfs: trace: set_verbose = 0 libguestfs: create: flags = 0, handle = 0x2428ec0, program = virt-resize libguestfs: trace: add_drive "/tmp/vbsrcbe72ee.img" "readonly:true" "format:raw" "protocol:file" libguestfs: trace: add_drive = 0 libguestfs: trace: add_drive "ubuntu-14.04.img" "readonly:false" "format:raw" "cachemode:unsafe" libguestfs: trace: add_drive = 0 libguestfs: trace: launch libguestfs: trace: get_tmpdir libguestfs: trace: get_tmpdir = "/tmp" libguestfs: trace: version libguestfs: trace: version = <struct guestfs_version *> libguestfs: trace: get_backend libguestfs: trace: get_backend = "direct" libguestfs: launch: program=virt-resize libguestfs: launch: version=1.24.5 libguestfs: launch: backend registered: unix libguestfs: launch: backend registered: uml libguestfs: launch: backend registered: libvirt libguestfs: launch: backend registered: direct libguestfs: launch: backend=direct libguestfs: launch: tmpdir=/tmp/libguestfsySDyNP libguestfs: launch: umask=0002 libguestfs: launch: euid=1000 libguestfs: command: run: /usr/bin/supermin-helper libguestfs: command: run: \ --verbose libguestfs: command: run: \ -f checksum libguestfs: command: run: \ --host-cpu x86_64 libguestfs: command: run: \ /usr/lib/guestfs/supermin.d supermin helper [00000ms] whitelist = (not specified) supermin helper [00000ms] host_cpu = x86_64 supermin helper [00000ms] dtb_wildcard = (not specified) supermin helper [00000ms] inputs: supermin helper [00000ms] inputs[0] = /usr/lib/guestfs/supermin.d supermin helper [00000ms] outputs: supermin helper [00000ms] kernel = (none) supermin helper [00000ms] dtb = (none) supermin helper [00000ms] initrd = (none) supermin helper [00000ms] appliance = (none) checking modpath /lib/modules/3.13.0-24-generic is a directory checking modpath /lib/modules/3.13.0-32-generic is a directory checking modpath /lib/modules/3.13.0-33-generic is a directory checking modpath /lib/modules/3.13.0-34-generic is a directory picked kernel vmlinuz-3.13.0-34-generic supermin helper [00000ms] finished creating kernel supermin helper [00000ms] visiting /usr/lib/guestfs/supermin.d supermin helper [00000ms] visiting /usr/lib/guestfs/supermin.d/daemon.img.gz supermin helper [00000ms] visiting /usr/lib/guestfs/supermin.d/init.img supermin helper [00000ms] visiting /usr/lib/guestfs/supermin.d/udev-rules.img supermin helper [00000ms] adding kernel modules supermin helper [00028ms] finished creating appliance libguestfs: checksum of existing appliance: 91a71afb6469a54392edcc914ff8a641915f545c14683266905f8f7ce855a8fd libguestfs: trace: get_cachedir libguestfs: trace: get_cachedir = "/var/tmp" libguestfs: trace: get_cachedir libguestfs: trace: get_cachedir = "/var/tmp" libguestfs: [00033ms] begin building supermin appliance libguestfs: [00033ms] run supermin-helper libguestfs: command: run: /usr/bin/supermin-helper libguestfs: command: run: \ --verbose libguestfs: command: run: \ --copy-kernel libguestfs: command: run: \ -f ext2 libguestfs: command: run: \ --host-cpu x86_64 libguestfs: command: run: \ /usr/lib/guestfs/supermin.d libguestfs: command: run: \ --output-kernel /var/tmp/guestfs.br7JCi/kernel libguestfs: command: run: \ --output-initrd /var/tmp/guestfs.br7JCi/initrd libguestfs: command: run: \ --output-appliance /var/tmp/guestfs.br7JCi/root supermin helper [00000ms] whitelist = (not specified) supermin helper [00000ms] host_cpu = x86_64 supermin helper [00000ms] dtb_wildcard = (not specified) supermin helper [00000ms] inputs: supermin helper [00000ms] inputs[0] = /usr/lib/guestfs/supermin.d supermin helper [00000ms] outputs: supermin helper [00000ms] kernel = /var/tmp/guestfs.br7JCi/kernel supermin helper [00000ms] dtb = (none) supermin helper [00000ms] initrd = /var/tmp/guestfs.br7JCi/initrd supermin helper [00000ms] appliance = /var/tmp/guestfs.br7JCi/root checking modpath /lib/modules/3.13.0-24-generic is a directory checking modpath /lib/modules/3.13.0-32-generic is a directory checking modpath /lib/modules/3.13.0-33-generic is a directory checking modpath /lib/modules/3.13.0-34-generic is a directory picked kernel vmlinuz-3.13.0-34-generic /usr/bin/supermin-helper: open: /boot/vmlinuz-3.13.0-34-generic: Permission denied libguestfs: command: run: rm libguestfs: command: run: \ -rf /var/tmp/guestfs.br7JCi libguestfs: trace: launch = -1 (error) Fatal error: exception Guestfs.Error("/usr/bin/supermin-helper exited with error status 1, see debug messages above") libguestfs: trace: close libguestfs: closing guestfs handle 0x2428ec0 (state 0) libguestfs: command: run: rm libguestfs: command: run: \ -rf /tmp/libguestfsySDyNP virt-builder: error: virt-resize failed pixel@akaran:~$ exit guestfstools version 1.24.5-1 installed via apt from ubuntu repo host ubuntu 14.04 kernel 3.13.0-34-generic x86_64 hardware vmware-fusion 6.04 with vt enabled. (on mavericks)