Windows Storage Server (WSS) 2012 is a bit of a dark horse as far as the storage industry goes. It doesn’t get a huge amount of press, which is unfortunate, since it now is a well-rendered “software-defined storage” system. It's designed to bring Windows-based file and block appliances to Windows Server 2012, Hyper-V, and MS SQL Server. It offers SMB and NFS interfaces for files and iSCSI for block, so it's very much an Ethernet solution.
Now, Violin Memory's new WSS 2012-based all-flash array brings super performance to WSS users and allows them to match the performance of all-flash arrays used on traditional Fibre-Channel SANs. This places Microsoft in the major leagues in storage, and gives it a story to match EMC and NetApp in terms of appliances.
Before getting into the details of the new all-flash array, let's look a little closer at WSS 2012 to get some perspective on what this new development brings. It’s a cloud-ready product with multi-tenancy support, and scale-out ability. External RAID storage can be connected to an appliance for storage expansion -- useful with bulk storage models, and legacy array re-use, though the choice of certified arrays is currently limited.
Versions of the code can deploy in Hyper-V virtual machines, making for a good deal of flexibility. With compression and block-level deduplication available across the Windows Server 2012 family as well as on WSS, concepts like source-based file size reduction offer benefits both in used storage capacity and network loading.
Microsoft has approached WSS 2012 from an enterprise-ready perspective, so robust features are available for failover and redundant pathing. This allows Microsoft to offer a large-scale enterprise version as well as a SMB "workspace" version with size and feature constraints. Products using WSS range from rackable appliances to small 4- to 6-drive tower systems.
Microsoft is responding to the changes in technology well. The Storage Spaces feature is designed to handle SSD and bulk storage tiering. Storage Spaces is a caching system, where hot data is moved to SSD, while cold data heads back to bulk HDD. Both read-caching and a write-back cache are provided so data being read and written benefit.
Storage Spaces provides a way for virtual desktops to be deployed quickly. Common files can be served up from deduplicated and compressed space, reducing load times, and VDI images can be delivered rapidly from SSD cache. This really speeds up loading, but doesn’t match the leading-edge performance of all-flash arrays.
Violin's WSS 2012-based all-flash array changes the picture by ramping up performance for WSS users.
The new Windows Flash Array appliance is more tightly coupled to application servers than typical flash arrays, and the performance metrics reported by Violin reflect that. The company claims speeds of around 2x the performance of a non-Windows flash array in an SQL Server setup, and of course this is way faster than a traditional HDD array.
Violin also discusses use cases such as VDI host storage and in Hyper-V environments. It claims radical real-life improvements in performance, run-time and latency. The new array promises capacities up to 256 TB by clustering, and the units are built standard with redundant WSS server blades, power, and fans for enterprise-standard operation.
The product is tuned to deliver data into the app server memory using SMB Direct and RDMA, which cuts out a lot of overhead and latency. More importantly, it reflects what a Software-Defined Storage system could look like in the future. The array is symbiotic with the host software environment, and tuned to the application use cases.
The architecture is tuned to in-memory SQL Server database operation, which benefits from the speed and low latency of data delivery directly into memory. Host-side compression/deduplication boost performance and reduce data footprints.
I expect we’ll see similar close-coupled solutions for VMware farms and VDI servers from EMC, with VMWare filing the role of collaborator and integrator that Microsoft has with Violin. If so, application server performance is well set to exceed Moore’s Law for a while, with the boost from in-memory operation compounded by super-fast app-sensitive arrays like the Windows Flash Array.
This may be the future of big iron storage companies, as the need for many large HDD arrays goes away, and inexpensive white-box bulk storage appliances and fast flash arrays take a larger share of the market. Indeed, that thought process may have fueled Red Hat's purchase of Inktank.