If it wasn't clear prior, Dell's recent acquisition of EqualLogic should make it clear that we are big fans of iSCSI. Truth be told, Dell has been a vigorous proponent of iSCSI since the early days. In fact, during my tenure at Intel helping to develop and drive iSCSI products, Dell was one of our main allies. As it stands today, Dell supports iSCSI across nearly all of its storage product lines: Dell EqualLogic PS Series, Dell|EMC AX and CX arrays, and the PowerVault MD and NX lines. However, it is not just Dell. The value of iSCSI is resonating with other vendors and customers. The result, iSCSI represents the fastest growing portion of the storage market growing 75% year over year in Q4 of 2007 (IDC, 2008). So, this all begs the question, why is Dell so hot on iSCSI?
Well, the answer for Dell is multi-faceted. There are the traditional value propositions based on the economic benefits of iSCSI. We love those benefits and are certainly important and impactful, but they are only part of the story. The truth is, the very nature of iSCSI enables innovative approaches to how storage systems built and how those innovative solutions are deployed. For example, EqualLogic's highly virtualized storage solution is, in many ways, facilitated by the nature of iSCSI. Because iSCSI rides above Ethernet, IP, and TCP, it accommodates more dynamic and flexible implementations. This is particularly important for virtual environments, and why we believe that iSCSI and Virtualization, both server and client, are like two peas in a pod. While they are pretty cool on their own, they are incredibly powerful when implemented together.
Contrast this with fibre channel and SAS; these protocols are very physically oriented. When I say physically oriented, I am talking about the OSI model where physical is the lowest level of the stack, and application is the highest. Because they are so low in the stack, flexibility is limited. In virtualized environments, these protocols require functionality compromises and additional configuration and points of management to reclaim a portion of that lost functionality, e.g. RDM and NPIV.
iSCSI, on the other hand, is infinitely flexible in comparison. As we have discussed in a few previous Power Solutions articles and in the press, iSCSI In virtualized environments is the only storage protocol that supports hypervisor arbitrated (VMFS/VMDK and VHD), hypervisor mapped (RDM), and what we have termed "Storage Direct"…the direct termination of storage connectivity within the guest operating system. This flexibility allows IT admins to choose the best model for each guest OS without the need to make functionality compromises. For storage-intensive applications that benefit from a more direct relationship with their storage resources, you have iSCSI "Storage Direct." For non-storage intensive workloads, you can stick with the hypervisor-arbitrated models. Learn more about these benefits here. iSCSI has further benefits when considering workload mobility and disaster recovery in virtual and non-virtual environments.
Again, it is not just Dell. Many customers and vendors are following our lead and are driving iSCSI into virtualized environments. Example, Network Appliance, http://www.infostor.com/display_article/311339/23/ARTCL/none/none/1/iSCSI-shines-in-virtual-servers,-blades/?dcmp=ISIDUS
IDC sees Virtualization as an ideal conduit for iSCSI. And check out the Internet. Just type "iSCSI and Virtualization" into your favorite search engine and enjoy.
The flexibility of iSCSI has great benefits today, but we believe it will be the backbone of greater innovation moving forward. This flexibility has significant benefits when considering client virtualization and other flexible computing models. It also has significant benefit when developing the next generation of data center management solutions featuring diskless servers and increasingly mobile enterprise workloads. I'll cover more on those topics in future posts. So, when considering the economic benefits, the innovative storage models it facilitates, and the unrivaled flexibility, it is hard not to be hot on iSCSI. Let me know what you think by posting a comment below, or by posting it on IdeaStorm.