AVM recently posted a few earnest questions on the Byte and Switch message board. In general, I find those anonymous boards to be bastions of hot-headedness, but AVM appeared sincere. So I posted a reply to hopefully answer the questions about benchmarks and caching in the network. Scroll down if you want to see AVM's questions first.
Glad to see the interest in Gear6 and CACHEfx. I’ll do my best to answer your questions and then perhaps invite topics requiring more detail to shift to our company blog, www.thoughtput.com.
Regarding benchmarks, there are differences. The benchmarks you mentioned are excellent for persistent storage systems. But the workloads that we see at our customers are different from the profiles of the SPC and SFS benchmarks. Our targets markets frequently have to handle heavy reads, small I/O operations, and intense metadata. So our benchmark used a workload generated with the SIO load generator from NetApp configured for 100% random read of the data. The load ran on 60 dual CPU, dual core, clients, 30 threads each, accessing a CACHEfx appliance with 768 GB of RAM-based cache capacity. The clients connected to a Fujitsu XG200C switch via eight 10 GbE links and the appliance connected to the switch with six 10 GbE links. The configuration also included a common NAS system.
In general, we prefer to focus our activities around specific customer workloads as they provide the best measures of value. Our NEMo I/O profiling tool is one way for us to get a good understanding of cache-ability for specific workloads. It is a simple script that requires no installation and can be a helpful indicator of caching success.
Regarding your point about where should the cache reside. We have, and will continue to see caching opportunities at all levels of the infrastructure. That said, some data centers will require significant caching investments. Caching on the controller or gateway only makes sense if every single storage controller or NAS gateway is going to be perfectly balanced with every other controller or gateway all the time.
On the other hand, if you believe in shifting hotspots and hot files across multi-controller environments then there are clear economic, performance, and management benefits to placing that caching resource in the network. If you have caching deployed in the network, it can scale independently from the end-systems. Now upgrading performance does not necessarily mean buying a new or additional subsystem, but rather being smart about adding cache that helps all existing subsystems.
This is an area we will continue to communicate further. Keep an eye on Thoughtput.com for more details. Thanks for your questions.
Gary Orenstein, Vice President of Marketing, Gear6
|Author: AVM IGNORE AUTHOR||Number: 1|
|Subject: value proposition||Date: 03/02/08 12:42 PM|
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