
df -hl
Filesystem      Size  Used Avail Use% Mounted on
/dev/xvda1      2.0G  1.6G  393M  80% /
devtmpfs        7.4G     0  7.4G   0% /dev
tmpfs           7.4G     0  7.4G   0% /dev/shm
tmpfs           7.4G  212K  7.4G   1% /run
tmpfs           7.4G     0  7.4G   0% /sys/fs/cgroup
/dev/xvdb        37G   49M   35G   1% /mnt


time virt-builder --cache /mnt fedora-20 
[   1.0] Downloading: http://libguestfs.org/download/builder/fedora-20.xz
#######################################################################   99.8%
[  88.0] Planning how to build this image
[  88.0] Uncompressing
[ 104.0] Opening the new disk
virt-builder: libguestfs error: /usr/bin/supermin-helper exited with error status 1.
To see full error messages you may need to enable debugging.
See http://libguestfs.org/guestfs-faq.1.html#debugging-libguestfs

real	2m29.110s
user	0m57.630s
sys	0m13.920s

