54

Chapter 4. Physical and Virtual Memory

the value indicates the rate at which pages of this type are decreasing. A value of zero indicates that

pages of this type are neither increasing or decreasing.

In this example, the last sample shows slightly over three pages per second being allocated from the

list of free pages (the

frmpg/s

field) and nearly 1 page per second added to the page cache (the

campg/s

field). The list of pages used as buffers (the

bugpg/s

field) gained approximately one page

every two seconds, while the shared memory page list (the

shmpg/s

field) neither gained nor lost any

pages.

4.7. Additional Resources

This section includes various resources that can be used to learn more about resource monitoring and

the Red Hat Linux specific subject matter discussed in this chapter.

4.7.1. Installed Documentation

The following resources are installed in the course of a typical Red Hat Linux installation and can

help you learn more about the subject matter discussed in this chapter.

  free(1)

man page   Displays free and used memory statistics.

  vmstat(8)

man page   Displays a concise overview of process, memory, swap, I/O, system, and

CPU utilization.

  sar(1)

man page   Produces system resource utilization reports.

  sa2(8)

man page   Produces daily system resource utilization report files.

4.7.2. Useful Websites

http://linuxperf.nl.linux.org/   The Linux Performance Tuning homepage. Provides a good in 

troductory overview of resource monitoring for performance tuning purposes. The mailing list,

unfortunately, appears to have been overrun by spam and is no longer used.

http://people.redhat.com/alikins/system_tuning.html   System Tuning Info for Linux Servers. A

stream of consciousness approach to performance tuning and resource monitoring for servers.

http://www.linuxjournal.com/article.php?sid=2396   Performance Monitoring Tools for Linux.

This Linux Journal page is geared more toward the administrator interested in writing a customized

performance graphing solution. Written several years ago, some of the details may no longer apply,

but the overall concept and execution are sound.

4.7.3. Related Books

The following books discuss various issues related to resource monitoring, and are good resources for

Red Hat Linux system administrators:

The Red Hat Linux Customization Guide; Red Hat, Inc.   Includes a chapter on many of the

resource monitoring tools described here.

Linux Performance Tuning and Capacity Planning by Jason R. Fink and Matthew D. Sherer; Sams

  Provides more in depth overviews of the resource monitoring tools presented here and includes

others that might be appropriate for more specific resource monitoring needs.