As you size the hardware for Hyper-V, I’m sure one of the things you do take a hard look at is storage. How much do you really want to spend to get the performance you want (or need)? There are a lot of storage options out there so it is very helpful to have a better idea of what the options are and how they impact your budget and performance. In Part 5 of the Server Virtualization Series, Bob Hunt gives a quick definition of the different storage options out there and why you might chose one over the other.
I am including a brief snippet of his article below, but you will want to go directly to his blog post to read the full article.
As we move through the 20+Days of Server Virtualization Series, the next topic we’re covering is Virtualization Storage. As a starting point for these next few posts on this topic, we’ll start out with some definitions of virtualization storage topologies used in conjunction with Windows Server 2012 server virtualization to set the stage.
As server-based workloads have migrated to virtualized platforms over the past several years, the storage platforms available to these server workloads have moved as well. For those customers using Windows Server 2012 Hyper-V, there are a myriad of storage options available to both the host (Windows Server 2012 Hyper-V server) and the virtual machine (guest operating system running on Hyper-V such as Windows Server 2012, Windows Server 2008 R2, Linux, etc.) These storage solutions offer various price points and performance characteristics that range from the most inexpensive solutions for small business to very fast, highly redundant solutions commonly used in large enterprises.
Below is a collection of storage platforms that are commonly used with Windows Server 2012 Hyper-V virtualization workloads
Direct Attached Storage (DAS) – Direct Attached Storage or “DAS” as it has become commonly known refers to a collection of hard disk drives housed in a storage enclosure that is located physically inside the Windows Server 2012 machine. These disk drives are typically connected via an embedded or PCI-based storage controller (SCSI, SATA, etc.) which communicate with the type of hard disk drives that are located in the disk enclosure. These drives are most often placed in a RAID (Redundant Array of Inexpensive Disks) to provide a fault tolerant storage volume for the host Windows Server 2012 server. Direct Attached Storage solutions are often the lowest cost storage option for virtualization storage since the internal RAID controllers common in these servers come at a much lower price point than the external storage controllers and subsequent storage networking components I’ll point out in some of the other storage solutions below. What’s unique about using Direct Attached Storage with Windows Server 2012 Hyper-V is that two servers with Direct Attached Storage can be configured to allow highly-available virtual machines using a feature called Shared Nothing Live Migration, so leveraging Direct Attached Storage doesn’t preclude customers needing highly available virtualization storage solutions.