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Optimize and troubleshoot disk performance.
It is possible to confuse a memory shortage that
causes paging with a disk bottleneck that
results in paging. As a result, when you
investigate the causes of paging, where a memory
shortage is not apparent, make sure to track
disk usage counters such as the following along
with memory counters:
Physical Disk\ % Disk Time
Physical Disk\ Avg. Disk Queue Length
Page Reads/sec with % Disk
Time and Avg. Disk Queue Length.
If a low rate of page-read operations coincides
with high values for % Disk Time and
Avg. Disk Queue Length, there could
be a disk bottleneck. If an increase in queue
length is not accompanied by a decrease in the
pages-read rate, then a memory shortage exists.
To determine the impact of excessive paging on
disk activity, multiply the values of the
Physical Disk\ Avg. Disk sec/Transfer and
Memory\ Pages/sec counters. If the
product of these counters exceeds 0.1, paging is
taking more than 10 percent of disk access time.
If this occurs over a long period, you probably
need more memory.
To check for excessive paging due to programs
that are running.
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Stop the program with the highest working
set value and see whether that dramatically
changes the paging rate.
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If you suspect excessive paging, check the
Memory\ Pages/sec counter.
This counter shows the number of pages that
needed to be read from disk because they
were not in physical memory.
Manage your paging file for better performance:
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Place a paging file on other disk drives.
If you have multiple hard disks,
splitting up the paging file will speed up
the access time. If you have two hard disks
and you split the paging file, both hard
disks can be accessing information
simultaneously, greatly increasing the
throughput.
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Increase the size of the paging file.
The recommended size for the paging file is
1.5 times the amount of RAM available on
your system.
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