I’ve been getting a lot of requests lately from people putting together massive storage “buckets” … 16 or more 1.5 or 2tb drives in a single array to provide a large storage container for whatever their data is (they don’t normally tell me that). However, they all so … “performance is not an issue”. This statement, IMHO, is basically a load of *^(*&%*&$%. Everyone is interested in performance … they just might not realise it straight away.

The question of which card to use often arises in these conversations. The 3 series card looks good because it’s cheap with lots of connectors … and price is a big consideration for these data “buckets”. So we discuss the various merits of 3 vs 5 series. “No, don’t need the performance of the 5 series” is a common statement. But what about, I ask, when things are not going so well.

The 3 series card is fine when your array is stable, optimal and all the planets are aligned, but what about rebuild times? This is where the 5 series with its extra grunt comes in handy. Rebuild times, impact on performance during a rebuild etc are questions that a lot of people don’t think about when building a system. In the past if you had a fairly small SCSI system it didn’t matter too much … the system could rebuild in the background relatively quickly without much impact on customer performance, but that’s not the case today.

When using large numbers of large drives rebuild time is an important factor. When using large numbers of sata drives impact on performance during a rebuild is also an important factor. So don’t think about specifying the products for your system for just the good times. Think about the bad times as well as make sure you put enough performance under the hood to (a) get you back up and running as quickly as possible and (b) not annoy the living daylights out of your users while this is happening.

Food for thought.

Ciao
Neil

This entry was posted on Wednesday, October 21st, 2009 and is filed under General, Storage Applications, Platforms, Storage Interconnects & RAID, Storage Management, Application Environments, Advisor - Neil. You can follow any responses to this entry through the RSS 2.0 feed. You can skip to the end and leave a response. Pinging is currently not allowed.