Scheduler does not distpatch VMs with RDM datastore images

Hi all

We have an issue with the scheduler and RDM images. We have included a new datastore and image (/dev/sdf) just following opennebula documentation (we are using opennebula 5.8.1):

https://docs.opennebula.org/5.8/deployment/open_cloud_storage_setup/dev_ds.html

the new datastore and image are created correctly but the problem is with the scheduler. The VM waits in a pending status and from the scheduler log we can see:

Fri Feb 14 12:54:35 2020 [Z0][VM][E]: Error deploying virtual machine 314 to HID: 8. Reason: [one.vm.deploy] Image Datastore does not support transfer mode: shared
Fri Feb 14 12:54:35 2020 [Z0][VM][E]: Error deploying virtual machine 314 to HID: 9. Reason: [one.vm.deploy] Image Datastore does not support transfer mode: shared
Fri Feb 14 12:54:35 2020 [Z0][VM][E]: Error deploying virtual machine 314 to HID: 7. Reason: [one.vm.deploy] Image Datastore does not support transfer mode: shared
Fri Feb 14 12:54:35 2020 [Z0][VM][E]: Error deploying virtual machine 314 to HID: 6. Reason: [one.vm.deploy] Image Datastore does not support transfer mode: shared

From oned.conf we are using the default values for “dev” datastores:

...
DS_MAD_CONF = [
    name = "dev",
    persistent_only = "yes",
    required_attrs = "DISK_TYPE"
]
...
TM_MAD_CONF = [
    clone_target = "NONE",
    ln_target = "NONE",
    name = "dev",
    SHARED = "YES"
]

Any idea why we are getting this scheduler error message? I have also changed the default SHARED = “YES” by NO but we get the same error message.

Thanks in advance!
Álvaro