Monitoring and Optimizing System Performance and Reliability

• Monitoring applications include Performance Console, Task Manager, and Scheduled Tasks.

• Performance Console consists of System Monitor and Performance Logs and Alerts.

  • Object A specific hardware or software component capable of being monitored.

  • Counter One of a series of statistical measurements associated with each object.

  • Instance A single item of multiple occurrences of a given object. For example, a dual processor computer has two instances of the processor: instance 0 and instance 1.

• The Performance Logs and Alerts snap-in enables you to log computer performance over time while the computer is executing other tasks.

• Performance logs are binary files that store performance statistics, which can later be analyzed.

• The Alerts branch of Performance Logs and Alerts enables you to display an alert when a selected counter exceeds or drops beneath a specified value.

• Table 13 describes important Memory object counters and how to resolve related problems.

Table 13. Important Counters for the Memory Object

Counter	What It Measures	Interpretation and Remedial Tips
Pages/sec	The rate at which data is read to or written from the paging file	A value of 20 or more indicates a shortage of RAM and a possible memory bottleneck. To view the effect of paging file performance on the system, watch this counter together with LogicalDisk\% Disk Time. Add RAM to clear the problem.
Available Bytes	The amount of physical memory available	A value consistently below 4MB indicates a shortage of available memory. This might be due to memory leaks in one or more applications. Check your programs for memory leaks. You may need to add more RAM.
Committed Bytes	The amount of virtual memory that has been committed to either physical RAM or running processes	Committed memory is in use and not available to other processes. If the amount of committed bytes exceeds the amount of RAM on the computer, you might need to add RAM.
Pool Nonpaged Bytes	The amount of RAM in the non paged pool system memory (an area holding objects that cannot be written to disk)	If this value exhibits a steady increase without a corresponding increase in computer activity, check for an application with a memory leak.
Page Faults/sec	The number of data pages that must be read from or written to the page file per second	A high value indicates a lot of paging activity. Add RAM to alleviate this problem.

• The Paging File\% Usage counter is of use when troubleshooting memory problems.

• By default, the paging file is located at %systemdrive%\pagefile.sys and has a default size of 1.5 times the amount of RAM in the computer.

• You might want to configure equal values for the initial and final paging file sizes. It is more efficient to increase the initial size of the paging file rather than to increase the final size. Increasing the final size of the paging file can force the operating system to allocate more space as applications start, thereby causing disk fragmentation. In most cases, configuring the option for Windows to select the best paging file size will work fine.

• Table 14 describes important Processor object counters and how to resolve related problems.

Table 14. Important Counters for the Processor Object

Counter	What It Measures	Interpretation and Remedial Tips
% Processor Time	The percentage of time the processor is executing meaningful actions (excludes the Idle process)	If this value is consistently greater than 85%, the processor could be causing a bottleneck. You should check the memory counters discussed previously; if these are high, consider adding more RAM. Otherwise, you should consider adding a faster processor (or an additional one if supported by your motherboard).
Interrupts/sec	The rate of service requests from I/O devices, which interrupt other processor activities	A significant increase in the number of interrupts without a corresponding increase in system activity may indicate some type of hardware failure. Brief spikes are acceptable.

• Table 15 describes important PhysicalDisk object counters and how to resolve related problems.

Table 15. Important Counters for the PhysicalDisk Object

Counter	What It Measures	Interpretation and Remedial Tips
% Disk Time	The percentage of time that the disk was busy reading or writing to any partition	A value of over 50% suggests a disk bottleneck. Consider upgrading to a faster disk or controller. Also check the memory counters to see whether more RAM is needed.
Avg. Disk Queue Length	The average number of disk read and write requests waiting to be performed	If this value is greater than 2, follow the same suggestions as for % Disk Time.
Average Disk Sec/Transfer	The length of time a disk takes to fulfill requests	A value greater than 0.3 may indicate that the disk controller is retrying the disk continually because of write failures.

• Table 16 describes important LogicalDisk object counters and how to resolve related problems.

Table 16. Important Counters for the LogicalDisk Object

Counter	What It Measures	Interpretation and Remedial Tips
% Disk Time	The percentage of time that the disk was busy servicing disk requests	A value greater than 90% may indicate a performance problem except when using a RAID device. Compare to Processor\% Processor Time to determine whether disk requests are using too much processor time.
Average Disk Bytes/Transfer	The amount of data transferred in each I/O operation	Low values (below about 20KB) indicate that an application may be accessing a disk inefficiently. Watch this counter as you close applications to locate an offending application.
Current Disk Queue Length	The amount of data waiting to be transferred to the disk	A value greater than 2 indicates a possible disk bottleneck, with processes being delayed because of slow disk speed. Consider adding another faster disk.
Disk Transfers/sec	The rate at which read or write operations were performed by the disk	A value greater than 50 may indicate a disk bottleneck. Consider adding another faster disk.
% Free Space	Percentage of unused disk space	A value less than about 10% indicates that insufficient disk space is available. Consider moving files, repartitioning the disk, or adding another disk.

• You should log disk activity to a different disk or computer. The act of recording performance logs places an extra "hit" on performance for the disk on which logs are recorded.

• You can modify an application's behavior by adjusting its priority in Task Manager or by starting the application at a different priority.

• Priorities for applications are Realtime (the highest priority, only to be used cautiously), High, AboveNormal, Normal (the default priority), BelowNormal, and Low.

• You can modify the application's priority in Task Manager or by using the start /option command.

• Table 17 describes options related to optimizing Windows XP performance.

Table 17. Performance Optimization Options

Section	Option	What It Does
Processor scheduling	Programs (default)	Assigns more processor resources to programs currently running in the foreground (active programs)
	Background services	Assigns equal amounts of resources to all programs, including those such as disk backup or defragmentation that are running in the background
Memory usage	Programs	Assigns a larger share of memory to running programs
	System cache	Assigns equal amounts of memory to running programs and to the system cache

• When an application doesn't function properly in Windows XP, you can run it in compatibility mode by selecting the Compatibility tab of the application's Properties sheet and selecting one of the compatibility modes.

• You can set processor affinity from Task Manager. Simply right-click the process from the Processes tab and choose Set Affinity. Then select the appropriate processor.

• The Scheduled Tasks applet is in Control Panel under Performance and Maintenance. You can also find it in the Accessories, System Tools menu. Table 18 describes options and controls found on the various tabs in the Scheduled Tasks dialog box.

Table 18. Functions of the Tabs of the Scheduled Tasks Properties Dialog Box

Tab	Functions
Task	You can specify which program is to be executed by typing the path to the file in the Run dialog box or by clicking Browse to locate the program. You can also specify additional parameters, optional comments, and set the user account and password. New to Windows XP SP2, you can specify that the task can run only if its user account is logged on.
Schedule	You can configure additional scheduling options, including modifying the dates and times at which the task will run.
Settings	You can modify additional settings that govern what happens when the task is completed, whether the task runs if the computer is not idle, and power management settings for running the task on portable computers.
Security	You can configure permissions for the user account(s) under which the tasks are to be run. This tab may not appear if SP2 is not installed.

• Remember the difference between standby and hibernation. If power is lost, data can be lost in standby mode because this mode does not save the desktop state to disk, only to RAM. However, the computer is able to resume activity more rapidly from standby than from hibernation. You should use hibernation if there is a danger of power loss, whereas you should use standby if rapid resumption is more important.

• For a Windows XP Professional computer to successfully hibernate, it must have available disk space in an amount that is greater than or equal to the amount of RAM installed in the computer.

• The preconfigured power management modes are

  • Home/Office Desk Maintains power for all components except the monitor

  • Portable/Laptop Powers down all components after 5 to 30 minutes of inactivity

  • Presentation Maintains power to the monitor as long as the computer is plugged in or running on battery

  • Always On Maintains power to all components of the computer indefinitely

  • Minimal Power Management Maintains power for all components except the monitor and disables timed hibernation

  • Max Battery Conserves as much battery power as possible

• You do not need a separate hardware profile for a fully Plug and Play-compliant computer used in a docking station. You do not need to create a profile if the portable computer is being used at a docking station. You can simply select the This Is a Portable Computer option.

• Hardware profiles specify which hardware drivers are loaded under specified conditions, such as when connected to the network or disconnected.

• Table 19 describes the five standard backup types in Windows XP.

Table 19. Five Standard Backup Types

Backup Type	Description
Normal or Full	Backs up all selected files and removes the archive bit, thereby indicating that the files have been backed up. Such a backup is the most complete backup and provides the fastest means of restoring data.
Differential	Backs up all files and folders that have changed since the last normal backup. It does not remove the archive bit; consequently this backup type accumulates all changes that have occurred since the last normal backup. Should you need to restore data, you need to restore the last normal backup plus the last differential backup.
Incremental	Backs up all files and folders that have changed since the last normal backup, and removes the archive bit. This backup type is the fastest one to perform, but it requires that you restore all incremental backups in sequence since the last normal backup.
Daily	Backs up all files and folders that have changed on the day the backup was made. It does not remove the archive bit.
Copy	Backs up all selected files, but does not remove the archive bit. This backup type is similar to the normal backup except for not removing the archive bit. It is useful for creating an extra backup for purposes such as offsite storage or producing a snapshot of a computer at a specified point in time.

• Understand the difference between incremental and differential backups. Incremental backups back up only files that have changed since the last normal or incremental backup; consequently, you must restore the normal backup and then each incremental backup in turn. On the other hand, differential backups back up all files that have changed since the last normal backup.

• Know who can back up which files based on default rights. Administrators and Backup Operators groups are able to back up and restore all files and folders; all users can back up and restore their own files and folders; users who possess the Read permission on a file or folder can back up that file or folder; users who possess the Write permission on a file or folder can restore that file or folder.

• System State data includes the Registry, Component Services Class (COM+) registration database, Boot files including system startup files, and files protected by Windows File Protection (WFP).

• The Windows backup command is ntbackup.

• Windows XP restores data backed up from Windows 2000, Windows XP, and Windows Server 2003 computers only. If you have backed up data in compressed mode from an older machine such as a Windows 9x/Me computer or have generated the .qic files by using Msbackup in Windows 9x/Me, you cannot restore this data to a Windows XP computer.

• Every time a user logs on successfully, Windows XP makes a recording of the current Registry settings, known as a control set. These settings are stored under HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet. This is made available as the Last Known Good Configuration the next time the computer is booted.

• Whenever you log on successfully after having made a damaging change to the computer, you cannot use the Last Known Good Configuration.

• Safe Mode with Command Prompt starts the computer to a command prompt. This can be useful if you cannot obtain a normal GUI.

• Safe Mode with Networking starts network drivers as well as the other basic drivers. This is useful if you need to copy files from a network location.

• You cannot use Safe Mode to repair corrupt drivers; you must use Recovery Console.

• The command to start the Recovery Console from the Windows XP installation CD-ROM that uses the drive letter D: is d:\i386\winnt32 /cmdcons.

• Automated System Recovery (ASR) is an advanced component of the Windows Backup utility and creates a backup of the system root files, as well as a floppy disk that contains data vital for booting the computer and beginning the restore process.

• The ASR restore process formats the system drive partition, losing any data added since the last backup.

• The ASR restore process checks the hard disk for errors and verifies the system files. You need to use the Windows XP Professional CD-ROM, the most recent ASR backup media, and the ASR floppy disk.