If vxodm driver was not properly loaded into kernel, then ODM cannot be started up and might produce an error like this:

# /etc/rc.d/rc2.d/S99odm start
Starting ODM...
No such file or directory: Warning: /usr/lib/drivers/vxodm.ext not loaded

First check if vxodm is loaded into kernel:

# genkex | grep odm
5374000 20110 /usr/lib/drivers/vxodm.ext_53

If you cannot see it, then check if the driver file exists, and try to re-load the driver with the following commands:

# /usr/lib/methods/vxkextadm vxodm unload
# /usr/lib/methods/vxkextadm vxodm load
# /etc/rc.d/rc2.d/S99odm start