Before implementing NAS clustering, you'll want to ask yourself the following questions:
- Do the data integrity features meet or exceed my firm's disaster recovery and data protection needs?
- Is proprietary hardware required? Or can I you use industry-standard processors and storage?
- Can third-party storage be used for the NAS cluster file serving solution? Or is the solution a proprietary one?
- What are the storage options in terms of SAS, SATA and Fibre Channel drives, or solid state drives, for the solution?
- How disruptive will it be to add new storage or replace existing storage?
- How disruptive will it to be to add storage to the NAS cluster or add NAS boxes to the a cluster?
- How are files spread across different nodes and the storage environment for access, capacity and availability?
- Which automated load-balancing features (performance, access and capacity) exist?
- Does a file system exist on one node, or can it be active across multiple nodes concurrently?
- Can storage be accessed by all file server nodes without shipping I/O between nodes?
- Are host software clients, agents or file systems required on either the client or the application servers?
- How does a NAS clustering solution leverage more nodes, processors, memory, networks and disks?
- What is the performance for different types of data access, such as large files? What about small files?
- What is the maximum amount of storage, file system size, file size and number of files supported?
More processors should equate to better performance. However, it comes down to how those processors are used by the software that determines actual performance. The best benchmark comparison is your own application running in a real world scenario or in lieu of that, looking at relative comparisons, such as specifications.
Your needs will ultimately determine whichever NAS cluster configuration you decide on. One myth about clustered NAS file serving solutions is that they're designed for high performance computing infrastructures. But not all clustered storage is targeted for high performance, and there are some high-performance storage systems that do not scale well. Do your homework and align the right type of clustered file serving solution to meet your particular needs and requirements.
About the author: Greg Schulz is founder and senior analyst with the IT infrastructure analyst and consulting firm StorageIO Group. He is also the author of the definitive book on storage networking, Resilient Storage Networks, published by Elsevier, and is a regular contributor to Storage magazine and other TechTarget venues. This was first published in May 2008
This was first published in May 2008