Dell SmartFabric Storage Software (SFSS) provides Centralized Discovery Controllers (CDCs) for NVMe/TCP Endpoints. These CDCs facilitate endpoint discovery, registration, soft zoning, and event notifications.
With SFSS, Dell Technologies provides the industry's first comprehensive connectivity automation solution for NVMe/TCP endpoints such as Dell PowerEdge, Dell PowerStore and Dell PowerMax.
You can install SFSS on a VMware ESXi host by deploying an OVA, or on Linux KVM by deploying a Qcow2 image.
Before the introduction of the CDC, NVMe/TCP was an end node-centric storage protocol where administrators would manually configure each host to connect to one or more Direct Discovery Controllers (DDCs) on the storage arrays. This manual configuration process was found to be error-prone and time consuming.
SFSS is designed to ensure that hosts can automatically connect to the appropriate NVM subsystem (array) interfaces by:
- Using mDNS to discover the available NVMe Discovery Controllers
- Using Get Log Pages to retrieve a list of IO interfaces that the host has been allowed to access.
For more detail on the messages exchanged between IP SAN components, see Automating the Discovery of NVMe-oF Subsystems over an IP Network.
Also, SFSS provides features that enable SFSS to provide a fibre channel-like user experience over the NVMe/TCP transport.
Fibre channel terminology | SFSS service name or function | Details of service and notifications |
Name Server Database | Discovery Service | NVMe/TCP endpoints dynamically discover the CDC |
Listen and respond to mDNS queries from endpoints in the fabric, where supported | ||
Endpoint Registration Service | The host and subsystem register their information with the CDC by sending discovery information that includes NQNs, IPs, symbolic names, and other information. | |
Endpoint Query Service | NVMe/TCP Hosts query the CDC to discover the NVMe/TCP subsystems they can communicate with | |
Zone Server Database | Zone Service | Zone Service details the soft zoning configured in SFSS. Get Log Page responses only include subsystems zoned for the querying host |
Registered State Change Notification (RSCN) | Asynchronous Event Notifications | Asynchronous Event Registration – subscribe to state change notifications from Endpoints |
Asynchronous Event Notifications – send notifications to Endpoints for state changes |
The following terms are used throughout this document.
- Endpoints
- Network interfaces on servers and storage platforms that are associated with an IP address and take part in the NVMe/TCP IP SAN.
- Centralized Discovery Controller (CDC)
- An NVMe Discovery Controller that typically runs in a centralized location and automates the discovery and registration of NVMe/TCP endpoints. Note: For a brief description of CDC features and functionality, see The NVMe/TCP Dating App blog post.
- Subsystems
- Storage target identified by an NVMe Qualified Name (NQN) known as a SUBNQN.
- Direct Discovery Controller (DDC)
- An NVMe Discovery Controller that runs on a subsystem (storage array) and is used by hosts to perform Direct Discovery, or can interact with a CDC to assist with discovery automation.
- CDC instance
- A logical division of interfaces in the SFSS VM. CDCs provide administrative separation between groups of endpoints.
To help avoid the potential impact of a configuration error, SFSS VMs are not synchronized with each other and do not fail over to each other. Best practice is to deploy two SFSS VMs for administrative and operational resiliency. To protect the VMs, leverage the resiliency tools provided by the hypervisor. In ESXi, HA, DRS, and FT are available. In Linux, OpenNebula can be used.