Top Three Reasons Not to Believe the Deduplication Appliance Datasheets : Reason #4 (There is always more)
To follow up on reason 2 (marketing metrics are not your metrics), I recently found another interesting case. I saw on the news that a major deduplication appliance vendor had just released new models. So, I downloaded and started reading their datasheets and technical presentations (as always), and one thing surprised me—the very high stream counts. The stream count was always accompanied by keywords such as “up to,” which means “less than or equal to,” so in other words nothing is guaranteed. Because the devil is always in the details, I searched for other keywords such as “concurrent (streams)” and so on without success. I also found strange figures, such as outbound replication stream counts higher than inbound, which is unusual. (Most customers need more “fan ins” than “fan outs.”)
For years, the main performance indicators for purpose built backup appliances have been the “ingest performance.” The maximum performance published on most vendors’ datasheets are the highest backup rates that the appliance can achieve in a very controlled environment. Usually, these rates are achieved starting with no data on the appliance, so that there is no deduplication occurring. Here again, there are a number of factors that influence the maximum ingest performance. These include how much redundancy is in the data being backed up, the number of backup servers and streams, and the age of the system.
Quantum has been providing storage and backup solutions for over 30 years — and we consider ourselves to be specialists in this market. Nonetheless, we do not control the rules of our own market (or its marketing). Bigger generalist players with unlimited marketing budgets often bend the rules, not always in the interest of customers. Here are three reasons not to believe everything they tell you in the deduplication appliance datasheets.