Fibre Channel HBAs (Host Bus Adapters)

Speed generations and reach

FC HBAs negotiate down to slower links, so a newer HBA can join an older fabric: QLogic states that its 16GFC 2690 Series cards are backward compatible with 4GFC and 8GFC, and Broadcom's Emulex LPe35000-series cards negotiate 32GFC, 16GFC and 8GFC automatically. Shortwave reach falls as speed rises:

Reach figures: QLogic's 2690 Series data sheet for 8GFC and 16GFC, Cisco's MDS transceiver data sheet for 32GFC.

FC generations and backward compatibility

Fibre Channel optics run at their own speed and the two below it, which is what lets new HBAs join older fabrics. Cisco's MDS transceiver data sheet gives each speed's autosensing range and optics:

Generation names are product names, not speeds: Broadcom markets its 32GFC Emulex HBAs as Gen 7, with NVMe over Fibre Channel alongside SCSI FCP, so read the speed on each listing. Most data center links use shortwave optics on multimode fiber; longwave optics cover single-mode runs between rooms or buildings.

WWPNs and zoning

Every FC port has a World Wide Port Name, an eight-byte identifier, and the SAN uses it to decide what the server can see. Brocade's Fabric OS lets a zone name a member by port WWN, which limits that zone member to the single port, and the storage array maps its volumes to host WWPNs. A replacement HBA brings new WWPNs, so plan to update the zones and the host entries on the array when you swap cards.

Fitting an FC HBA

An FC HBA is the server end of a SAN: it reaches the storage arrays through Fibre Channel switches. QLogic builds its 2690-series cards on PCIe 3.0 x8 and Broadcom builds the LPe35000 series on PCIe 4.0 x8, so both suit an x8 or wider slot, such as the up to eight PCIe 3.0 slots of a PowerEdge R740; blade mezzanine versions fit blade servers instead. Check each listing for the bracket height and for whether optics ship with the card; FC optics are on optical transceivers.

For directly attached shelves and tape, see SAS HBAs; for SAN storage itself, storage arrays, and the background in SAN vs NAS vs DAS. Each HBA carries an Enterasource warranty whose term is on its listing. All adapter types: host bus adapters.

Cards that carry Fibre Channel over Ethernet instead are on converged network adapters.

Fibre Channel HBA questions

Will a 16Gb FC HBA work with an 8Gb SAN switch?

Yes. A 16GFC port autosenses 16, 8 and 4GFC, per Cisco's MDS optic data sheet, and QLogic states its 16GFC cards are backward compatible with 4GFC and 8GFC, so the link comes up at 8GFC. Use optics rated for the slower speed on the switch side, and keep the fiber within the 8GFC reach for its grade: 150 m on OM3 with shortwave optics.

What is the difference between an FC HBA and a converged network adapter?

An FC HBA speaks native Fibre Channel to FC switches; a converged network adapter carries Fibre Channel over Ethernet (FCoE) and iSCSI alongside normal LAN traffic. FCoE needs Ethernet that does not drop storage frames, which Cisco provides with priority flow control and a switch acting as a Fibre Channel forwarder. Choose by the SAN you already run.