Solid Data Systems: I/O Dynamics -- I/O Dynamics was developed by Solid Data to analyze the impact of disk activity on system performance in specific customer applications.

Proven Applications Expertise

Solid Data Systems has years of experience working with I/O-bound applications, assisting our customers in determining which files are hot. Our experience enables us to identify hot files and advise our clients which files to move to solid-state disk (SSD) in order to achieve the most dramatic performance improvements for their applications.

Of all the solid-state disk manufacturers and vendors, only Solid Data provides system-level analysis software. Solid Data has developed proprietary software technology called I/O Dynamics™ which eliminates one of the traditional limitations of solid-state disk storage - the difficulty involved in identifying hot files. While the mainframe database market has always been prepared to invest the time and expertise required to determine which files were hot, we recognized that the midrange Unix and NT server markets would not be as willing or able to make this up-front investment. Because of this, we developed I/O Dynamics - proprietary expert software that analyzes the impact of disk activity on system performance. The software enables automated identification of hot files in new applications and provides precise information for rebalancing the system periodically after the initial installation. An I/O Dynamics Impact Analysis offers our clients a risk-free way to understand what SSD can do for them.

I/O Dynamics Overview

I/O Dynamics was developed by Solid Data to analyze the impact of disk activity on system performance in specific customer applications. Solid Data has invested several man-years and over one million dollars in the development and perfection of the proprietary analytical concepts embedded in the I/O Dynamics expert system, and we are in the process of applying for a patent on these innovations.

The program consists of two parts:

System Activity Resource (SAR) scripts that are run at the customer site to collect both system and disk activity data simultaneously, in a manner tailored for analyzing the dynamics of system response as a function of disk system I/O. The output of these scripts is then forwarded to Solid Data for analysis and evaluation.
Analytical suites that transform and group the data for determination of relationships and causality. By applying sophisticated time domain and differential mathematics, I/O Dynamics is able to identify the logical-devices having the greatest impact on peak load conditions and to quantify that impact in the context of the customer's application - as opposed to an artificial test environment. In many cases, there are logical-devices that constitute only a small percentage (3-5%) of the overall storage capacity, but they comprise over half the I/O service load.

Accordingly, I/O Dynamics is a useful tool in understanding system I/O bottlenecks and identifying candidate logical-devices for assignment to SSD, with the objective of significantly reducing overall I/O service times. SSD is very effective in accomplishing this goal because it is not constrained by the mechanical delays inherent in disk drives, resulting from actuator seek times and rotational latencies. Because of this, logical-devices transferred to SSD typically demonstrate an improvement of over 90% in average service and response times.

When combined with system architecture information concerning the logical size of candidate volumes, the output of I/O dynamics can be used specifically to evaluate which volumes provide the best economics for the introduction of SSD into the system architecture.

Sample I/O Dynamics Impact Analysis-Executive Summary

A study has been completed for XYZ Company relative to its Sendmail Server application currently comprised of the following major components:

Operating System: SunOS implementing NFS
Server platform: Sun Ultra2
DRAM architecture: 2-Dimensional using main memory and disk cache

The I/O Dynamics Impact Analysis resulted in the following overall conclusions:

The system shows clear evidence that I/O service times are constraining overall system performance to a significant degree. Specifically, the system is "waiting for I/O" an average of 44% of the time; making disk I/O wait-time the single largest component of system resource utilization. It is clear that disk service times are limiting the overall processing capacity of this Mail Server. Addressing this problem with SSD will have a significant positive impact on overall system output, resulting in faster response times and more room for future load increases.
From a total of three logical-devices, one is creating the large majority (over 71%) of constraining activity during peak load conditions. This logical-device is identified from the I/O Dynamics analysis as MD1.
This logical-device is an excellent candidate for assignment to SSD, with the resulting outcome being an estimated reduction in "I/O Wait" time of greater than 70%. This, in turn, will free up system resources for handling a greater mail load.

Based on these results, Solid Data makes the following recommendations:

The subject Mail Server can benefit greatly from a 3-Dimensional DRAM architecture that incorporates solid-state storage (SSD) as a means to accelerate the identified "hot file" that is significantly restricting overall system throughput. (See Solid Data's White Paper "Building a 3-D DRAM Architecture for Optimum Cost/Performance" for more information).
MD1, containing the queue spool for Sendmail mail queue, is the primary candidate for assignment to SSD.

In Solid Data's opinion, XYZ Corporation can improve the overall load-processing capability for its Mail Server by more than 200% by incorporating a Solid Data file-caching system as a fundamental component of the architecture for handling high-activity files that are inherent to this application.

Example of Actual I/O Dynamics Analysis Results:

Before:

The color blue represents wasted CPU cycles (I/O wait state)

After:

Solid Data's file-caching system eliminated wasted CPU cycles, resulting in a four-fold workload increase!

Interested in an I/O Dynamics Impact Analysis to see what kind of system improvements YOU could expect from Solid-State Disk?

Register now to qualify or call 1.800.287.0373 and ask to speak to Sales. Please mention you are calling regarding the offer you saw on our Web site to qualify for an I/O Dynamics Impact Analysis.