Part 1: Overview
By Lawrence Gavin, Head Geek, SolarWinds®, Virtualization & Storage Management
Storage management will likely be the most important near-term consideration for organizations looking to invest in virtualization. The importance here is to select the correct storage methodology for the virtualization environment being built (there are more choices available today than there were five years ago), and to ensure that the correct management tools exist for managing both the storage infrastructure and the hosts and virtual machines utilizing those services. More to the point, the key is to not get locked into the wrong storage methodology.
Many VMware® environments started off as large-scale clustered environments and are typically backed by SANs. Hyper-V environments, on the other hand, typically have been organically grown, one standalone host at a time, and built on top of direct attached storage (DAS). This works fine for organizations with just a few hosts, but beyond that, managing individual DAS environments on a per-host basis becomes tedious, burdensome, and inefficient.
Storage performance has typically been driven by one major factor: spindles. Historically, SANs were needed to get large quantities of spindles. Spindles cost money. So does a SAN infrastructure. Equally as relevant are the constraints in the storage fabric itself. You can only attach so many spindles to a 16Gb Fibre Channel (FC) Host Bus Adapter (HBA) before you run out of bandwidth in the I/O channel. Bottom line: implementing and growing a SAN is expensive.
However, with the advent of 40Gb and 100Gb Ethernet connections, there’s a whole new world available from iSCSI—and now, Windows Server® 2012 Server Message Block (SMB) 3.0 and all of its associated improvements in file services. As a result, virtualization hosts are no longer beholden to the “power of the SAN.” Shucks, even dual-port or quad-port 10Gb Ethernet NICs can be teamed to provide 2-3x the available bandwidth of a 16Gb FC HBA.
More significantly, Windows Server 2012 file servers can be incrementally added to a file services cluster as more resources are needed, rather than having to invest the full Monty up front (as is often necessary with a SAN infrastructure). In this three-part series, we’re going to take an in-depth look at two key considerations for using file services as a storage methodology for Hyper-V.
• Part 2 – File Services Enhancements: Part two will provide an overview of new file services in Windows Server 2012 that improve the value for virtualization. This new version of Windows Server brings significant improvements in failover clustering, cluster shared volumes, scale-out file servers, cluster-aware updating, storage migration, improvements in the SMB protocols, and for those who do have SANs, the addition of fibre channel adapters in the guest OS for VM storage performance.
• Part 3 – Cost Comparison of SMBv3 vs SAN Expansion: In the final part of the series we will provide a cost comparison of adding incremental storage with Windows Server 2012 file services versus adding additional fabric and disks with a SAN. In this article, we’ll look at acquisition and implementation costs involved in adding additional storage capacity to a SAN environment compared to expanding a Windows Server 2012 file services cluster using scale-out file servers.