Virtual HBAs Hitch Servers & Storage

As users look to wring more efficiency out of their storage systems, HBA vendors are cranking up efforts to tie storage and virtualization more closely together. (See 3Leaf Teams With Emulex and QLogic Sets Record With SANblade.)

Emulex, for example, recently announced plans to integrate its virtual HBA technology with Linux-based systems, following a similar deal between Emulex and Microsoft. (See Emulex HBA Joins Linux Kernel.) A VMware-compatible Emulex virtual HBA, which was announced in 2006, is also on the cards for sometime later this year.

A virtual HBA is essentially a piece of firmware that runs on a physical HBA, enabling it to interact with Virtual Machines (VMs), which in turn are software instances that let users run separate applications or even operating systems on the same piece of hardware.

Virtual HBAs are supposed to make it easier to manage VMs in SAN environments. Enabling virtual machines to access a dedicated HBA effectively opens up the virtual infrastructure to fabric switches from the likes of Brocade, Cisco, and McData. In this way, applications running on virtual machines no longer appear as a single entity and can also be individually encrypted. (See Tales From the Virtual Crypt.)

With many IT managers forced to rethink their storage infrastructure to better fit virtualization, demand is also growing for HBAs that fit, according to Scott McIntyre, vice president of customer and software marketing at Emulex. "We're seeing huge uptake in adoption of server virtualization technologies, and that is driving a fairly high attach rate to Fibre Channel SANs."Emulex, of course, is keen to push its HBA technology, although at least one analyst agrees that it makes sense to build virtualization into hardware. "It offers improved performance compared to running it on software," says Eric Ogren of analyst firm the Ogren Group, explaining that this typically offers much faster processing of data.

Without virtual HBAs, performance and manageability can be issues. McIntyre explains that virtualization limits the effectiveness of techniques such as zoning and LUN masking, which ensure that storage from one server is not allocated to another.

The situation prompted Emulex and IBM to develop a protocol called N Port ID Virtualization (NPIV), which essentially fences off one virtual machine's storage from another. IBM has been shipping the Emulex HBA with its z-Series mainframes for over two years. The HBAs link virtual machines in the mainframe environment to Fibre Channel SANs. But Emulex has been keen to extend the reach of the technology to open systems.

Earlier this year, Emulex integrated its NPIV-based HBA with Microsoft Virtual Server. The networking vendor is ahead of rival QLogic in this regard, which plans to launch a Microsoft-based Virtual HBA of its own sometime later this year. (See QLogic, Microsoft Partner.)

QLogic told Byte and Switch that, like Emulex, it has also inked a deal with VMware.QLogic is just as enthused about virtual HBAs as Emulex, viewing it as part of a brave new virtual world. "If an IT manager was asked to put in a SAN for a new workgroup, instead of buying a new switch or a new HBA, or a new server, they can buy a piece of the HBA, a piece of a switch, and a piece of a server," says Frank Berry, director of corporate marketing at QLogic.

James Rogers, Senior Editor Byte and Switch