Determining the Trend
It is important to understand that the rate of increase dictates how far in advance additional organization virtual datacenter resources need to be purchased. The following table presents a sample virtual machine forecast for a quarter along with sample “time to purchase” value.
Table 17. Sample Organization Virtual Datacenter Trending Information
Attribute | Value |
ΔNcpuUC | 12 |
ΔNmemUC | 12 |
ΔNVGB | 360GB |
Tpurchase | 2 weeks |
NcpuUC,cluster | 320 |
NmemUC,cluster | 717 |
In this example, NcpuUC,free and NmemUC,free represents the number of free resources within an organization virtual datacenter at which point additional organization virtual datacenter resources should be ordered. To determine the trigger point for ordering use the following equation if no pipeline data exists.