esaProbeStorageType is a create-time StorageType value describing whether this ESA Probe row's configuration is kept in volatile or non-volatile storage. An administrator relies on it to know whether a probe's configuration will survive a device reboot or needs to be re-provisioned from a management system afterward. For example, a probe provisioned with a non-volatile storage type stays configured and testing after a card reset, while one left volatile disappears and must be recreated by the SLA management application.