Server Virtualization, Desktop Virtualization, Big Data and the overwhelming growth of unstructured data are stretching current Network Attached Storage (NAS) systems to their breaking point. This is forcing storage managers to scramble for solutions to address their performance and capacity limitations without resorting to rip and replace upgrades.

NAS vendors embrace a “throw hardware at it” approach to solving the problem, and add a tier of SSD. The problem is that SSD is expensive hardware to throw. Most of these implementations are not optimized to take full advantage of SSDs performance capabilities. Just adding SSD to a system doesn’t resolve other bottlenecks that will impede the SSD.

Adding SSD to an existing NAS unit will only help so much. These other bottlenecks need to first be resolved before any benefit from an SSD investment can be derived. For instance, steps should be taken to reduce latency, improve NFS efficiency, augment metadata handling and enhance network performance. If all of these measures are followed, less becomes more - the SSD is used more efficiently and the caching appliance doesn’t require excessive CPU and loads of memory to generate high NFS OPS. When all of the bottlenecks of storage performance are resolved, a newly deployed NAS acceleration appliance will drive the required performance and the original NAS can be relegated to a data management repository with plenty of CPU cycles given back, by way of the ANX 1500, to store and protect more data.

Alacritech’s ANX 1500 addresses NAS performance issues and resolves performance bottlenecks. As an external appliance that sits between the NAS and the user application, the ANX 1500 is designed to offload performance workloads from the NAS, improve application/user response time, reduce storage related costs, and eliminate NAS sprawl in the data center.

The first step towards accelerating NAS performance is to leverage memory based cache storage in the form of DRAM and flash. The ANX 1500 takes it a step further by utilizing its acceleration technology, leveraging both silicon and software to place data in its cache with minimal latency to intelligently service the most active data sets. Its primary goal is to offload the majority of read requests from the NAS so that it can focus on only managing write traffic.

Splitting the workload in this fashion reduces dependency on the NAS's hard disk drives and frees up NAS processing resources for other functions like data protection (RAID, snapshots, replication). Alacritech goes a step further and delivers key differentiation from other products on the market by efficiently managing the NFS protocol, improving metadata handling and providing overall enhancements with network efficiency.

As an example, the ANX 1500 improves the efficiency of Layer 7 NFS so that it can more effectively respond to NFS requests. This further frees up the NAS processor/controller resources while improving NFS metadata performance. Metadata contains the data about the data. Information like path location, create date, access date, modification data, backup status as well as advanced snapshot information are all metadata attributes. In the modern NAS, referencing metadata can equate to as much as 90% of all I/O requests. The ANX 1500 offloads the NAS from processing this information by caching the metadata and as a result, accelerates metadata responses. This further reduces NAS CPU resource consumption and minimizes network chatter.

NAS Vendors Fall Short

NAS vendors are of course, attempting to solve NAS storage I/O problems within their own platform. Their solutions include installing PCIe SSDs into the NAS’ PCIe slots or via HDD form factor SSD through the NAS' SAS/SATA controller bus and drive shelves. There are problems to each approach. First, available PCIe slots are extremely limited in NAS systems. At best, one or two slots may be available. Secondly, form factor SSD performance is constrained by the controller bus path.

Both approaches are dedicated to a single NAS system from a single NAS vendor. Again, neither approach typically addresses NFS and metadata performance issues. Network based caching appliances, on the other hand, don't have the siloed limitations of a dedicated NAS cache and can be implemented with a wide variety of vendors and systems.

Storage Swiss Take

Alacritech has a long history of delivering performance optimization solutions. They have now applied this expertise to NFS acceleration. The combination of DRAM and flash caching, plus NFS and metadata optimization, leads to excellent performance improvements. The ANX 1500 is an excellent example of a product and company truly trying to solve a problem instead of just throwing hardware at it. As NFS continues to proliferate in data center environments, this offering will provide IT decision makers with a viable option for enhancing performance.

Alacritech is a client of Storage Switzerland

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