In addition to storage capacity, the following diagram summarizes the areas where sizing considerations apply:
Accuracy in size : estimates vs. real-world measurements
Sizing of infrastructure based on estimates is an inexact science.
EcoSys is a highly configurable software product. Because of this, the workload from different users, configurations, and requirements varies from implementation to implementation.
Shared resources introduce external variables that affect performance. External variables include shared storage, database clusters, networks, and especially virtualized environments.
Infrastructure resources can cause response times to scale nonlinearly with user load. Twice the hardware may not always support twice the workload with the same response times.
Initial estimates may not be accurate, and real-world data volume and concurrent user load may vary.
Growth in data volume and concurrent user load over time may require further analysis for appropriate infrastructure sizing.
For these reasons, the only certain way to predict performance is to measure it on real-world hardware. The guidelines in this document should be taken as general estimates, not exact calculations, even though they are formulaic in their approach.