Windows Server How-To
Windows Server 2012 R2: Exploring Storage Tiering
Brien puts the new tiered storage feature through the ringer to see what hidden hardware requirements are needed to run smoothly.
One of the most anticipated new features in Windows Server 2012 R2 is tiered storage. In case you have not heard about this new feature, the basic idea is that a storage pool can consist of both mechanical hard drives and solid-state drives. This allows the solid-state drives to act as a repository for frequently read blocks. The "hot blocks" are written to solid-state storage so that they can be read more quickly than would be possible if they resided on traditional mechanical hard drives. Best of all, Windows automatically moves blocks to solid-state storage, and does so dynamically based on how frequently a block is used.
Although the concept of native tiered storage sounds enticing, it is important to stop and consider the underlying hardware requirements. Obviously, one or more solid-state drives are required, but are there any additional hardware requirements?
Windows Server 2012 R2 is still in the preview phase and to the best of my knowledge the official hardware requirements have yet to be released. However, I have spent a considerable amount of time over the last few weeks working with the tiered storage feature and have made an important observation.
When I first began experimenting with the new operating system, I installed it onto an old server that I wasn't using. To be completely honest, the server really wasn't all that old. It contained a quad-core processor and was probably about three years old. Since the server didn't have any solid-state storage, I purchased a solid-state drives that I could install into the server because I wanted to see how the new tiered storage feature worked.
Although the server was able to access the solid-state disk, I found that the operating system was unable to differentiate between my solid-state drive and the other hard drives in the system.
At first I thought that perhaps I had done something wrong, so I started looking more closely at how my storage pool was configured. If you open the Server Manager and navigate to File and Storage Services | Volumes | Storage Pools, you are able to select a storage pool and see the physical disks that are included in the storage pool. The Physical Disks list includes a number of different columns.
Although it was initially off the screen, scrolling to the right revealed a column named Media Type. The Media Type column was empty. Normally, this column should differentiate between HDD and SDD.
As far as I can tell, the problem occurred because the system's BIOS was not designed to detect solid-state storage. This meant that I was not able to use the tiered storage feature. I actually had to purchase a new server so that I could begin experimenting with this feature. Once I plugged the drives into the new server, the Server Manager was immediately able to differentiate between media types and I was able to configure the tiered storage feature.
I honestly don't know at this point with the official hardware requirements will be for tiered storage. If my experience is any indication however, it seems that tiered storage can only be used on hardware that is relatively new. In order to use tiered storage, Windows must be able to differentiate between hard disk drives and solid-state drives, and this can only happen if the underlying hardware is also able to make the distinction.
If Windows is unable to make the distinction then it will treat solid-state drives as if they are mechanical hard drives. In other words, you can include the solid state drives in a storage pool and use them to store data, but you will not be able to use them as a storage tier. Hopefully, Microsoft will publish definitive hardware guidelines closer to the actual Windows Server 2012 R2 release.
Brien Posey is a 16-time Microsoft MVP with decades of IT experience. As a freelance writer, Posey has written thousands of articles and contributed to several dozen books on a wide variety of IT topics. Prior to going freelance, Posey was a CIO for a national chain of hospitals and health care facilities. He has also served as a network administrator for some of the country's largest insurance companies and for the Department of Defense at Fort Knox. In addition to his continued work in IT, Posey has spent the last several years actively training as a commercial scientist-astronaut candidate in preparation to fly on a mission to study polar mesospheric clouds from space. You can follow his spaceflight training on his Web site.