iSCSI + NAS for virtual servers?

October 8, 2009 – When end users first started the mass migration to virtual servers, the majority did so with direct-attached storage (DAS) as the underlying storage architecture. They quickly found out that virtualization required networked storage, and the incumbent SAN protocol – Fibre Channel – became the front runner in the race toward dominance in server virtualization storage architectures.

Fibre Channel SANs are still the dominant storage architectures in virtual operating environments, but iSCSI – and also NAS – are coming on strong.

In an infostor.com QuickVote poll (conducted last year), we asked virtual server users what their primary storage configuration was. More than half (53%) cited Fibre Channel SANs, 28% were relying primarily on iSCSI, 10% on NAS, and only 9% on DAS. Since then, I’m sure the percentages for iSCSI and NAS have shifted upward.

That survey didn’t ask whether users were combining different storage architectures to support their burgeoning virtual server implementations. However, combining SANs and NAS appears to be a strong trend.

In an end-user survey, Enterprise Strategy Group (ESG) posed the following question:

Does your organization have plans to consolidate NAS and SAN storage resources into a unified storage architecture that supports both file-based NAS and block-based SAN storage?

With the caveat that the question was not posed in a virtual server context, it’s interesting to note that well over half of the respondents (67%) planned to pursue a “unified storage” (SAN+NAS) strategy. In fact, 18% were already underway – and the ESG survey was conducted late last year.

Among those that are moving to unified storage architectures, 41% plan to rely primarily on NAS gateways to front-end SANs; 18% plan to rely primarily on unified NAS-SAN storage systems; and 40% plan to use both approaches.

If you’re among the growing group of users that are deploying iSCSI + NAS architectures – particularly if you have virtual servers – check out our Webcast, “Unified Storage for Virtual Servers: iSCSI SANs and NAS.” If you missed the "live" version earlier this week, you can view the archived version here.

ESG analyst Terri McClure presents interesting data from ESG’s end-user surveys and discusses trends in the context of unified storage and virtual servers. And John McArthur, president and co-founder of Walden Technology Partners, discusses solutions that enable you to combine iSCSI SANs and NAS to optimize efficiencies in virtual server environments – at a low cost and with minimal management overhead.

Choosing the right storage architecture for your virtual server environment is not an either-or decision.