In the context of HPE StoreOnce Catalyst and NAS replication, security is governed by a bi-directional trust or permission-based handshake. When configuring replication between two StoreOnce appliances, the "Target" (Secondary) system acts as the gatekeeper. The error described occurs because the primary system is attempting to push data or create a mapping to a destination that has not authorized it.

According to the HPE StoreOnce documentation regarding Replication Permissions, the secondary appliance must explicitly grant permission to the source appliance before any mapping or data transfer can occur. This is a security measure designed to prevent unauthorized data ingestion or "rogue" replication tasks from consuming storage resources on the target system. To resolve the permission error, the administrator must log into the Secondary StoreOnce appliance (the target) and navigate to the replication settings. There, they must add the Primary StoreOnce appliance as an authorized "source" by specifying its network address (FQDN or IP) and providing the necessary credentials (username and password) that the primary system will use to authenticate.

Unlike simpler protocols where a "Public Access" setting (Option B) might exist, HPE StoreOnce requires a defined relationship for NAS and Catalyst replication to ensure data integrity and multi-tenancy security. Option A refers to token-based authentication, which is more common in modern cloud-native Alletra environments via DSCC, but not the standard for legacy StoreOnce NAS replication. Options D is incorrect because the permission must be granted at the receiving end, not the sending end. Once the secondary system has the primary's details stored in its Replication Permissions list, the primary appliance will be able to successfully "discover" the target libraries and establish the mapping without further permission errors.