The Business Argument for Higher Storage Utilization
Posted Wednesday, June 01, 2011 in Technology 0 comments
Here’s a scenario for you. You’re put in charge of manufacturing operations for your company, which is selling the widgets you make as fast as you can make them. You discover that you are running your manufacturing operations at 35% of capacity. What would you do?
First, you’d probably ask why. Then you’d probably compare the cost of running them at a much higher utilization rate with the additional revenue from sales. Chances are that you would almost immediately move to a plan that more fully utilizes your existing production capacity.
In introducing your company to server virtualization technology, you may have made a somewhat analogous argument to executive management. If you were running your physical server infrastructure at roughly 15-20% of its capacity (which, by the way, is pretty much on target with what most companies were doing), that left a lot of capacity that you had already paid for unused. As you grow and need more computing capacity, you could add more servers, using 15-20% of each new server, or you could look at an approach which increases utilization of existing servers first to accommodate growth and help keep costs down. In moving to server virtualization technology, you could promise your company that you would easily triple server capacity utilization while at the same gain some other benefits in the areas of flexibility to adapt to an evolving business environment, easier management, and lowered energy costs. Bottom line: this change will allow us to get a lot more out of the IT infrastructure that we pay for.
When you made the move to virtual servers, chances are you stayed with the same old storage architecture. Sure, maybe you moved to a networked storage environment so you could more fully leverage what server virtualization had to offer, but the underlying storage architecture was the same. Why? The same capacity utilization issue exists with legacy storage architectures that existed with physical servers and with the manufacturing capacity example above. If you’re like most companies that have moved to virtual servers, you’re running your storage about a third as efficiently as it could be run.
There are two key facets to this definition of “efficiency”: performance and capacity. IOPS/spindle is a relevant measure on the performance side for most application environments, while the amount of allocated storage capacity relative to the amount that is actually used is the key one on the capacity side. Because of the extremely random, very write-intensive I/O patterns generated in most virtual computing environments, the IOPS/spindle you get from spinning disk in these environments is about a third of what you would get from that same disk running in the old client/server model with one application running on a dedicated physical server. And because you’re already at a disadvantage in terms of IOPS/spindle, you may have decided against using the native thin provisioning technology included with the major hypervisors (ESX, Hyper-V, XenServer) to address the “efficiency of space utilization” issue – you can’t afford the performance hit.
If you apply the same logic used above for the manufacturing and initial move to virtual servers, you’d start looking for a way to increase the “efficiency” of your storage. A very cost-effective way to increase the IOPS/spindle you get out of your existing storage is to install Virsto. Relative to native hypervisor thin provisioned virtual disk technology, we’ve seen IOPS/spindle increases of from 3x (for FC disk) to 10x (for high capacity SATA disk). Virsto’s pure software solution installs at the hypervisor level (not in the guest VMs), works with any block-based storage, and generally increases the “efficiency” of your storage by 3x or more.
The business benefits are pretty obvious. You use a lot fewer disks to meet your performance requirements, you’re generating a lot more IOPS/spindle so you can work with thin provisioned disks to save on storage capacity, and you end up being able to support a lot more VMs with any given storage configuration. Using a lot smaller storage configuration to meet your performance requirements also reduces secondary storage costs for things like backup and disaster recovery, saving even more money.
Maximizing utilization of infrastructure you’ve already paid for is a good thing. You’d do it for manufacturing, you’ve done it for servers, why not do it for storage too?
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