flashcache failed

[wazzgod]

First time user of flashcache, what am i doing wrong?

rpm -Uvh http://elrepo.org/elrepo-release-6-4.el6.elrepo.noarch.rpm
yum --enablerepo=elrepo-testing install kmod-flashcache flashcache-utils

dd if=/dev/zero of=disk-image count=20480000

/sbin/mkfs -t ext4 -q disk-image

mount -o loop /root/disk-image /vz

flashcache_create -p thru -s 10g vz /dev/mapper/sil_biaebhbhfaaa /dev/loop0

[root@2503-10008 ~]# flashcache_create -p thru -s 10g vz /dev/mapper/sil_biaebhbhfaaa /dev/loop0
cachedev vz, ssd_devname /dev/mapper/sil_biaebhbhfaaa, disk_devname /dev/loop0 cache mode WRITE_THROUGH
block_size 8, cache_size 20971520
Flashcache metadata will use 40MB of your 24158MB main memory
Size of cache volume (/dev/mapper/sil_biaebhbhfaaa) is larger than disk volume (/dev/loop0)
Are you sure you want to proceed ? (y/n): y

device-mapper: reload ioctl on vz failed: Device or resource busy
Command failed
echo 0 20480000 flashcache /dev/loop0 /dev/mapper/sil_biaebhbhfaaa vz 2 2 8 20971520 140733193388544 8 | dmsetup create vz failed
[root@2503-10008 ~]#

Here are some general info about my server. (OS / partitions / mounts / ect)
http://pastebin.com/raw.php?i=kMiTJvid
If you need more info please let me know.