The Rise and Fall of Cisco Storage Virtualization

The Early Days of MDS SAN Virtualization When Cisco introduced the MDS 9000 line of storage switches in 2002, it took the storage industry by storm.  It was quickly identified as a different kind of storage switch, one that was capable of intelligence far beyond the existing storage switches of the time. Cisco forged close alliances with many vendors, who adopted the MDS as OSM's (Original Storage Manufacturers), and even developed products and functionality around the product line.  Cisco refers to these types of services as Intelligent Fabric Services.  Over the years, there have been a number of changes to the types of services offered with the MDS.  But in my opinion it is not going in a positive direction and certainly not quickly enough. Here is a brief summary of some of the types of Intelligent Fabric Services that have existed on the MDS line: HardwareProductLatest SAN/NX-OSLatest SSI ImageDS-X9032-SMV Advanced Services Module (ASM)Veritas’ Storage Foundation for Networks2.1(1a)ASM 2.1(1a) VSFN 1.1 FP 1DS-X9560-SMC Caching Services Module (CSM)IBM SAN Volume Controller (SVC)1.3(4a)CSM 1.3(5m) SVC 1.1.8DS-X9032-SSM Storage Services Module (SSM)EMC Invista3.3(3)3.3(3)Cisco Data Mobility Manager (DMM)4.2(5)4.2(5)Fibre Channel Write-Acceleration4.2(5)4.2(5)SANTap4.2(3a)4.2(3i)Incipient NSP4.1(3a)4.1(3a)MDS-9222iCisco Data Mobility Manager (DMM)5.0(1a)5.0(1a)Storage Media Encryption (SME)5.0(1a)5.0(1a)Cisco Secure Erase5.0(1a)5.0(1a)SANTap4.2(3a)4.2(3i)DS-X9304-18K9 MSM 18/4Cisco Data Mobility Manager (DMM)5.0(1a)5.0(1a)Storage Media Encryption (SME)5.0(1a)5.0(1a)Cisco Secure Erase5.0(1a)5.0(1a)SANTap4.2(3a)4.2(3i)Incipient NSP4.1(3a)4.1(3a)DS-X9316-SSNK9 SSN-16Cisco Data Mobility Manager (DMM)5.0(1a)5.0(1a)Storage Media Encryption (SME)5.0(1a)5.0(1a)Cisco Secure Erase5.0(1a)5.0(1a) In the beginning, Cisco had the CSM (Caching Services Module), this was the first fabric based storage virtualization solution.  Unfortunately its life was short lived.  This module ran IBM's SVC, a storage virtualization product that still lives on today, although no longer being actively developed on the MDS hardware.  Shortly after, Cisco released the ASM (Advanced Services Module) which was designed for companies to write applications that took advantage of this hardware. The only application I am aware of that was produced was Vertias' Storage Foundation for Networks.  This product still exists today but is not a fabric based application.  I do believe that both of these storage virtualization applications were in-band, even though they were installed in the MDS.  Another popular storage virtualization application is EMC Invista.  This product stopped being supported when the MDS's switched to 4.x and Generation 2 modules.  Invista was unique because of its split-path architecture which it still uses today.  The product is alive today, but not being actively developed on the MDS platform.  The oldest living of the storage virtualization applications that took advantage of the MDS's Intelligent Services was Incipient's NSP.  I am not sure what exactly happened with Incipient.  The software was good, it competed with EMC Invista, as it also used a split-path architecture.  It sold some of its intellectual property to Texas Memory Systems and their website seems to be dead.

Outdated Hardware The MDS is a great platform for companies to partner with for intelligent fabric services.  The SSM module for example support NASB, FC Write-Acceleration, SANTap and supports Fabric Application Interface Standard (FAIS)-based Intelligent Storage Application Programming Interface (ISAPI).  But what happened to all the apps?  The SSM was a good platform, but one of the main problems with it is that it is a Generation 1 module.  If you stick a Generation 1 module into a chassis with Generation 2 modules, you dumb down the capabilities to an extent.  For example, the number of port indexes drops to 252 if you have a combination of Generation 1 and Generation 2 modules, this is significantly below the limit of 1020 port indexes that exists in Generation 2 architecture.  If you have a 9513 chassis, and want to put a bunch of 48 port blades into it, you will be quickly disappointed once you find out that after 252 ports no more are recognized.  The SSM admittedly  was dated, as it was a 32 port 1/2GB module.  Although best practice is not to directly connect devices to the SSM (Unless you have to, for example for SCSI Flow Services/FC Write Acceleration).  I would have thought Cisco could have updated this module, maybe make it 1/2/4GB based, Generation 2 and continue to grow its alliances with vendors. It's true you can purchase a SSN-16 or MSM 18/4 module and overcome the obstacles outlined above.  However, neither of these are taken advantage of by any companies with regards to SAN Virtualization.  Companies may use certain features like NASB or FAIS, but nothing with the type of intelligence that could exist today.  I am sure the SSN-16 supports just as much as the SSM and a whole lot more, it certainly has a ton of horsepower.  What I am looking for are the specific alliances and partnerships where storage manufacturers are tightly integrating with the fabric manufacturers to make storage provisioning and storage reclamation easier than ever.

Who is selling this stuff anyways? I personally think the MDS is one of Cisco's most poorly marketed products.  I think its because Cisco really does not go to market directly with the MDS, rather it relies heavily on storage OSM's and storage integrators to position its storage switches.  The OSM's however choose to use the MDS for storage transport but prefer to use other companies for intelligent services, in many cases its themselves.  I think the manufacturers felt that why share the storage intelligence landscape with a network company like Cisco, and abandoned ship.  I think that was a bad move, because today its all about alliances.  Networks are converging and Cisco brings a lot to the table.  Cisco doesn't market the MDS the same way as it markets its network products, it's sort of a sleeping giant - a huge amount of deployed ports, but not really a presence that shows that.  Today, storage is a bigger than ever.  Even though a a lot of the talk is FCoE and other converged technologies, the MDS is still relevant, with Cisco announcing FCoE intentions for the MDS platform and continued support with its Nexus / NX-OS product lines.

The MDS's Untapped Potential Today you have a lot of players in SAN Virtualization: HDS, FalconStor, 3PAR, Compellent, Symantec, IBM, etc.  Some of these are storage based and some of them are fabric based.  Many companies are upgrading their SAN's to new generation technology.  They end up with many heterogenous silos of storage which are perfect for the deployment of SAN Virtualization.  HDS and NetApp seem to understand this perfectly as both are pushing their SAN virtualization abilities.  I think both of these companies could enhance their offerings by partnering with Cisco and taking advantage of the fabric. Only a fabric based solution is going to be able to do cool things like create virtual targets/virtual initiators transparently, including using various NAT-like functionality so you can essentially hijack the existing target FCID's so you don't have to re-zone all your servers and reconfigure a lot of equipment. Cisco has formed alliances with EMC and NetApp which it has recently been touting.  I would say that I have seen a stronger show of force with the EMC / Cisco relationship than the NetApp / Cisco relationship.  I would very much like to see more tighter integration between Cisco and NetApp.  For example, NetApp's replication offering SyncMirror, requires Brocade switches.  You can't use MDS switches!  Hopefully that one gets changed soon, because I like both companies and a Cisco / NetApp replication storage would be a great offering. So let me take a step back. I like fabric services and innovation.  But what good is an intelligent fabric or storage array if they don't work together?  It's time the focus be put on storage provisioning and storage virtualization.