ScottK's blog

The last post looked at frequency of  cluster asymmetry, and what types of asymmetry (memory, CPU, etc.) are more common. To quickly recap, a third of clusters sampled showed some kind of asymmetry. Amount of memory and server models were the most common type of asymmetry. CPU speed & CPU model were the least common.

First, thanks to those who wrote me, both online and offline, about my last post on the distribution of cluster node counts. As a follow-up, here’s a look at cluster asymmetry – that is, how often a cluster’s nodes are not identical. This is a non-academic question, since we’re in the process of adding new servers to SORT’s cluster.

I was thinking about cluster node counts the other day, and wondering about their distribution. That is, what percentage of clusters are two node, three node, four node, and so on.

Some of the data I plan to analyze in this blog involve scale/size, including utilization. I've heard industry analysts and experts cite storage utilizations rates around 40%; Nicholas Carr recently spoke at Symantec and noted that at roughly 30%, storage was much more utilized than CPU (~12%).

As the January 2011 issue of CIO Digest noted, a recent Gartner survey revealed data growth was the most cited IT concern for 2011 by large enterprises. One option to reduce disk storage growth is Thin Provisioning. Thin Provisioning allocates storage as needed, yet stays completely transparent to applications.