Performance Monitoring

Running header: PERFORMANCE MONITORING

Performance Monitoring

Introduction

The task for this week's assignment is to discuss specific common areas of concern in reporting hard drive, network, and memory issues, explaining what to look for in these areas.

Overview

Regular performance monitoring ensures that administrators always have up-to-date information about how their servers are operating. When administrators have performance data for their systems that cover several activities and loads, they can define a range of measurements that represent normal performance levels under typical operating conditions for each server. This baseline provides a reference point that makes it easier to spot problems when, or before they occur. In addition, when troubleshooting system problems, performance data gives information about the behavior of the various system resources at the time the problem occurs.

Hard Drive Monitoring

There are many factors that need to be monitored to determine the performance of a hard drive system. For the purpose of this paper, I will be focusing on two areas that I feel are important. They are disk space and disk efficiency.

Disk space is important to monitor because some applications may fail to run if they can't allocate the required space needed to work. Also, low disk space can limit the ability of the paging file to grow as needed, which in turn affects the system's virtual memory. If the paging file can't grow then virtual memory is severely limited which could slow down or crash a system.

Using the built-in monitoring utility Performance Monitor (Perfmon.msc), under the category Add Counters/Performance Object/LogicalDisk, there are two counters that can be used to monitor disk space. They are "% Free Space" and "Free Megabytes". The % Free Space counter displays the percentage of total usable free space on the selected logical drive or drives. This is a much better indication of free space than right clicking the drive and viewing its properties. The Free Megabytes counter basically provides the same type of information, but in a different format. It displays the available free space in megabytes instead of percentages. If after running these counters it's determined that space is running low, the administrator should try running "Disk Cleanup" from within Performance Monitor, compress the hard drive if feasible, or move some files to another disk drive.

Monitoring disk efficiency is a little more complicated than monitoring free space, but is necessary to ensure that the disk drives are running at peak performance. There are a few steps that should be taken prior to monitoring disk efficiency. They are:

* Save disk logs to a different hard drive if possible so they don't interfere with the disk's performance by being written to the disk being tested.

* Be sure to defrag the disk drive before testing. Testing a severely fragmented drive will only return poor results because of the amount of seek time required to look at each sector of free space.

* Be sure the disk to be monitored is not compressed or encrypted because this will only add time to the results.

For best results, you would want to test the drive for maximum throughput. To do this requires the use of more counters than what was used for the free disk space tests. The recommended counters are listed below and should be monitored from the both objects PhysicalDisk and LogicalDisk. They are:

* Avg. Disk Bytes/Read - the average number of bytes transferred from the disk during read operations.

* Avg. Disk Read Queue Length - the average number of read requests that were queued for the selected disk during the sample interval.

* Avg. Disk sec/Read - the average time, in seconds, of a read of data from the disk.

* Disk Read Bytes/sec - the rate at which bytes are transferred from the disk during read operations.

* Disk Reads/sec - the rate of read operations on the disk.

Once the results of the tests have been gathered and it's determined that the maximum throughput could be better, try adjusting the load on the disk to increase performance and prevent it from becoming a bottleneck on the network.

Network Monitoring

Reliable communication across a network is extremely important in today's work environment. Similar to disks on a system, the behavior of the network has an impact on the operation of your computer. The best way to optimize a system's performance is to analyze the network's traffic and resource utilization. The two primary tools to do this are the Network Interface Object which is part of the Performance Monitor, and Network Monitor which needs to have the driver installed on the system you want to test, and then gets configured via the Control Panel.

There are a total of 17 different counters to use under the Network Interface Object to help determine a network's reliability. The counters that I'll be focusing on are:

* Output Queue Length - the length of the output packet queue (in packets). If this is longer than two, there are delays and the bottleneck should be found and eliminated if possible. Since the requests are always queued by the Network Driver Interface Specification (NDIS) in this implementation, this will always be 0.

* Packets Outbound Discarded - the number of outbound packets that were chosen to be discarded even though no errors had been detected to prevent transmission. One possible reason for discarding packets could be to free up buffer space.

* Bytes Total/sec - the rate at which bytes are sent and received over each network adapter, including framing characters. Network Interface\Bytes Received/sec is a sum of Network Interface\Bytes Received/sec and Network Interface\Bytes Sent/sec.

The set of counters listed below will be available once the Network Monitor driver has been installed on the computer and configured. They are:

* Broadcast Frames Received/sec - used to establish a baseline when monitored over time to