Occur Kernel Panic when start instance in Xen Environment

Hello, I tried to Xen+Nova Deployment. (I tried to step by step by http://wiki.openstack.org/XenServerDevelopment)

I have one xen hypervisor(192.168.0.156) and one guest vm(192.168.0.104).
I installed a nova to guest vm.
this is nova.conf
---------------
--verbose
--nodaemon
--sql_connection=mysql://root:password@127.0.0.1/nova
--network_manager=nova.network.manager.FlatManager
--image_service=nova.image.glance.GlanceImageService
--flat_network_bridge=xenbr0
--connection_type=xenapi
--xenapi_connection_url=https://192.168.0.156
--xenapi_connection_username=root
--xenapi_connection_password=password
--xenapi_inject_image=true
--rescue_timeout=86400
--allow_admin_api=true
--flat_injected=false
--ca_path=/root/openstack/nova/CA
--glance_api_servers=192.168.0.104:9292
-----------------

when i booted a vm,
#nova boot test --flavor 2 --image 3

there are occur kernel panic. console output(I can see this message from xencenter) is
[ 0.378732] RAMDISK: Couldn't find valid RAM disk image starting at 0.
[ 0.379149] VFS: Cannot open root device "xvda1" or unknown-block(0,0)
[ 0.379154] Please append a correct "root=" boot option; here are the available partitions:
[ 0.379162] Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0)
[ 0.379168] Pid: 1, comm: swapper Not tainted 2.6.32-23-server #37-Ubuntu
[ 0.379172] Call Trace:
[ 0.379181] [<ffffffff81556fca>] panic+0x78/0x137
[ 0.379188] [<ffffffff8187f240>] mount_block_root+0x1ea/0x29e
[ 0.379193] [<ffffffff8187f34a>] mount_root+0x56/0x5a
[ 0.379198] [<ffffffff8187f4be>] prepare_namespace+0x170/0x1a9
[ 0.379203] [<ffffffff8187e829>] kernel_init+0x146/0x156
[ 0.379209] [<ffffffff810141ea>] child_rip+0xa/0x20
[ 0.379215] [<ffffffff810133d1>] ? int_ret_from_sys_call+0x7/0x1b
[ 0.379220] [<ffffffff81013b5d>] ? retint_restore_args+0x5/0x6
[ 0.379225] [<ffffffff810141e0>] ? child_rip+0x0/0x20

I uploaded Ubuntu image(kernel, ramdisk, machine) from http://173.203.107.207/ubuntu-lucid.tar
and success to upload to glance.

# glance index
Found 3 public images...
ID Name Disk Format Container Format Size
---------------- ------------------------------ -------------------- -------------------- --------------
3 lucid_ami ami ami 524288000
2 kernel aki aki 4099360
1 ramdisk ari ari 7988037

now, nova said instance is active,

# nova list
+----+--------------+--------+-----------+-------------------+
| ID | Name | Status | Public IP | Private IP |
+----+--------------+--------+-----------+-------------------+
| 12 | test_diablo3 | ACTIVE | | [u'192.168.0.51'] |
+----+--------------+--------+-----------+-------------------+

but, I can't anything because kernel panic.

How can I fix this problem? help me plz