Problem

This error could be caused by a volume being exported outside of
OpenStack using a host name different from the system name that
OpenStack expects. This error could be displayed with the IQN <iSCSI
Qualified Name (IQN)> if the host was exported using
iSCSI.

2013-04-19 04:02:02.336 2814 ERROR cinder.openstack.common.rpc.common [-] Returning exception Not found (HTTP 404)
NON_EXISTENT_HOST - HOST '10' was not found to caller.

Solution

Host names constructed by the driver use just the local host name,
not the fully qualified domain name (FQDN) of the Compute host. For
example, if the FQDN was myhost.example.com, just
myhost would be used as the 3PAR host name. IP
addresses are not allowed as host names on the 3PAR storage server.