Case Study #1
Home Up

What's New
Patz Etc.
Search/Site Map
Contact Us




This project involved an underperforming SUN configuration. When the customer sought a complete system upgrade,
we recommended that the system be studied first to determine what needed upgrading.

After several days of system monitoring, modeling, and careful analysis, we determined that this installation was data-starved (I/O bound CPU wait averages 66%), but there was sufficient CPU capacity.


 We found that the I/O subsystem was constrained and working beyond its rated capacity. We polled the disk controller to study the individual disks and found the following:



The x-axis names the individual disk devices while the y-axis shows the % busy. It is clear that some disk volumes are too busy to meet the requirements of data transfer to the CPU.

When we considered the block characteristics of the disk arrays, we noticed a serious non-linearity.

Upon analysis of this anomaly, we determined that outside consultants had loaded all database and file indices on vol 07.


Our recommendation was to add a new disk array and redefine the placement of files from vol 07 across the new storage system.

 Result: Customer saved over $300,000 on an unnecessary system upgrade and still achieved desired performance.

to top of page


Further information


Next Case Study


Contact Us


Our Methodology

Jerrold Patz "Jerrold Patz" computer consulting "behavior modeling" "forensic engineering" "patz consulting"