Keeping in mind that the best server and storage IO is the one that you do not have to do, then second best is that which has the least impact combined with best benefit to an application. This is where SSD, including DRAM- and NAND-flash-based solutions, comes into the conversation for storage performance optimization.
One sure way to improve performance is to cache the non-dynamic data of any application. We did this to improve the overall performance of The Virtualization Practice website. However, there are many places within the stack to improve overall performance by caching, and this got me to thinking of all the different types. At the last Austin VMUG, there were at least three vendors selling caching solutions that were designed to improve overall performance by as little as 2x to upwards of 50x improvements. That is quite a lot of improvement in application performance. Where do all these caching products fit into the stack?
In part II of this series we covered some of the differences between various Hard Disk Drive (HDD) including looking beyond the covers at availability, cache and cost. Let us pick up where we left off on our look beyond the covers to help answer the question of which is the best HDD to use.
Unless you are one of the few who have gone all solid-state devices (SSDs) for your virtual environment, hard disk drives (HHDs) still have a role. That role might be for primary storage of your VMs and/or their data, or as a destination target for backups, snapshots, archiving or as a work and scratch area. Or perhaps you have some HDDs as part of a virtual storage appliance (VSA), storage virtualization, virtual storage or storage hypervisor configuration. Even if you have gone all SSD for your primary storage, you might be using disk as a target for backups complimenting or replacing tape and clouds. On the other hand, maybe you have a mix of HDD and SSD for production, what are you doing with your test, development or lab systems, both at work and at home.
With Virtual Desktop Infrastructures (VDI) initiatives adoption being a popular theme associated with cloud and dynamic infrastructure environments a related discussion point is the impact on networks, servers and storage during boot or startup activity to avoid bottlenecks. VDI solution vendors include Citrix, Microsoft and VMware along with various server, storage, networking and management tools vendors.
A common storage and network related topic involving VDI are boot storms when many workstations or desktops all startup at the same time. However any discussion around VDI and its impact on networks, servers and storage should also be expanded from read centric boots to write intensive shutdown or maintenance activity as well.