Emulex is buying Aarohi. What is the appeal? Emulex has been a Fibre Channel I/O company. It supplies host bus adapters (HBAs) linking servers to Fibre Channel (FC) cables. It also supplies switching technology to be used inside disk arrays, courtesy of a previous Vixel acquisition. Such switching speeds up I/O within a drive array between the drives and the controller by adding more bandwidth and resilience.

Thus Emulex sells products that fill in the gaps between servers and the storage area network (SAN) fabric on the one hand, and between disk drives and the controller in an array on the other. It has been parlaying this into doing more with a trio of initiatives.

Extending Emulex' SAN gap-filling
One is to virtualise HBAs so that virtual servers can use the same physical HBA but have their various SAN I/O traffic streams kept apart and their access into the SAN limited.

Another is to connect SANS together or add in Ethernet (iSCSI) access to a SAN by providing a router.

The third is to enable SATA Drives to be communicated with by a Fibre Channel port on a drive array containing Fibre Channel disks with its developing FC-SATA protocol.

Emulex is not at the SAN heart
So Emulex has been busy at the edges of the SAN fabric and between SAN fabrics. It has not had a presence inside SAN fabrics though.

Emulex has also responded to the idea of having SAN facilities based on Ethernet, on using SCSI commands sent in IP, iSCSI, across Ethernet links, with the Ethernet link and the drive arrays forming an IP SAN. The company has an initiative with Intel to build TCP/IP processing offload engines (TOEs) and provide server access to iSCSI SANs in the same way with HBAs it provides server access to FC SANs.

But this is, it seems to me, an edge activity that misses the main opportunity with iSCSI SANs. What is this big opportunity?

iSCSI opportunity
A Fibre Channel SAN has its fabric and fabric intelligence is being used to provide SAN storage applications. Thus EMC's InVista and IBM's SAN Volume Controller (SVC) are software platforms providing storage management applications running in or alongside SAN fabric directors such as Cisco's MDS 9000, Brocade's SilkWorm and McData's Intrepid.

Each director is having a hardware and software platform added to/alongside it to provide the dedicated processing resource to run InVista or the SVC. In McData's case it is called an Application Services Module (ASM) and is based on Aarohi chips and software.

Aarohi is working with several storage suppliers. The list includes EMC, FalconStor, Incipient, Kashya, NetApp (Alacritus), Revivio, StoreAge and Symantec (Veritas). Like Emulex it has an OEM business model.

Unlike Emulex it has technology that can fill in the missing link in the IP SAN business.

An iSCSI SAN has no equivalent network fabric to a Fibre Channel SAN. It uses Ethernet as the transport and dumb boxes - routers, bridges - to switch the traffic. But the same storage applications are going to be needed. In an iSCSI SAN people are still going to want storage virtualisation, volume management, provisioning, data migration, replication, virtual tapes, continuous data protection and backup.

It can't be done in the iSCSI SAN fabric because there isn't one. (We have previously commented on this FC SAN/IP SAN mismatch.) So it has to be done either in front of the storage arrays or in front of the accessing servers. Aarohi has hardware and software technology to do this.

1 + 1 = 3
Aarohi has an Intelligent Storage Processor (ISP) chip and software. It is using this to help OEMs develop storage application platforms that can provide the equivalent of SAN fabric intelligence for IP SANs. The ISP-based boxes sit in front of the storage drive arrays or in front of servers, particularly blade servers.

By buying Aarohi Emulex inherits its current OEM relationships and thus has an entry right in the heart of the FC SAN fabric. It also positions itself wonderfully well to become a pre-eminent supplier of intelligent IP SAN storage management platform hardware/software to the iSCSI storage vendors. They will like it, presumably, because they can offer more of a complete solution, a one-stop IP SAN shop.

Emulex will be able to provide virtualised storage I/O to virtualised servers. This I/O can be FC or IP-based and be routed to virtualised FC SAN arrays or IP SAN arrays. The storage resources can be virtualised, managed, replicated, provisioned, protected, whatever.

Like Aarohi, Emulex is a firm believer in standards. Emulex is driving FC-SATA through the Storage Networking Industry Association (SNIA) and Aarohi is a supporter of the Fabric Application Interface Standard (FAIS).

The entire IP SAN movement just got a tremendous infusion of enabling technology that could make all the difference between the success or failure of IP SANs.

All in all it looks like an acquisition made in business heaven. There will be some very happy people sitting around the board table in Emulex right now. Aarohi stock holders will also be ecstatic. They will be sharing out $39 million and already ordering trousers with deeper pockets.