Freemem is freeware. It lets you see the values of some of the kernel parameters, thresholds, and values that will give you a really good idea about how memory is being used by HP-UX. This utility is a spinoff from our development of SarCheck for HP-UX, and we're providing it for free as a way of thanking the HP-UX community for the success of SarCheck. The default output of freemem looks like this:
freemem= 1612 gpgslim= 133 lotsfree= 535 desfree= 133 bufpages= 3275 dbcminpgs= 3276 dbcmaxpgs= 6554 minfree= 33 for info: freemem -help
You can timestamp the output and get rid of the message at the end with the -q and -t switches, and you'll get this:
14:55:37 freemem= 1568 gpgslim= 133 lotsfree= 535 desfree= 133 bufpages= 3275 dbcminpgs= 3276 dbcmaxpgs= 6554 minfree= 33
More information about switches can be found in the usage text. This page contains the usage text, license text, information on how to interpret freemem's output, how to graph freemem output with gnuplot, and finally, a downloadable copy of freemem.
requirements
Resource utilization is trivial. You do not need to be root to run freemem. The one binary seems to work properly on operating systems from 10.10 to 11.22, with 32-bit or 64-bit operating systems, and with both PA RISC and Itanium systems. It was compiled on a PA RISC system and will use more CPU time on an Itanium, but CPU utilization should still be a small fraction of a second of one processor's time.
usage text
usage: freemem [-q] [-t] [-license] -q don't append messages to the end of the output line -t precede the output with a timestamp -license send the license agreement to stdout This program sends the values of various pstat data to stdout in a parsable format. Any invalid argument or incorrect number of arguments will cause this usage text to display instead of the expected data. This program was designed to gather datafrom the pstat interface and make it available for use by human performance analysts or by our SarCheck performance analysis utility. More information about SarCheck can be found at www.sarcheck.com Please take a look at the license agreement for this program. It's free to use and distribute, and the details can be seen by using the -license switch, ideally piped to more because it's about 70 lines long. We hope that it helps you to better understand the way your system uses memory. Copyright 2002 by Aptitune Corporation, Plaistow NH USA http://www.aptitune.com/ http://www.sarcheck.com/
license text
Aptitune Corporation PO Box 1033, Plaistow NH 03865 USA email: sales@sarcheck.com Phone: 1-603-382-4200; Fax: 1-603-382-4247 http://www.sarcheck.com FREE SOFTWARE LICENSE AGREEMENT TERMS AND CONDITIONS CAREFULLY READ ALL THE TERMS AND CONDITIONS OF THIS AGREEMENT. USING THIS PROGRAM CONSTITUTES YOUR ACCEPTANCE OF THESE TERMS AND CONDITIONS. If you do not agree to the following terms and conditions, no license is granted hereunder and you are not authorized to use Aptitune Corporation's freemem program. 1. LICENSE: Aptitune grants to you a royalty-free, worldwide, perpetual, right and license to use the Program, including the right to make copies of the Program. YOU MAY NOT DECOMPILE, REVERSE ENGINEER, OR OTHERWISE DISASSEMBLE OR MODIFY THE PROGRAM OR ANY PART THEREOF. 2. In the event that you copy or transfer the Program, you agree to reproduce the Program in its entirety, including the copyright notice. 3. TERMINATION: This license will terminate immediately and without notice upon your failure to comply with any term or condition of this Agreement. You agree, upon such termination, to destroy all copies of the Program. 4. NO WARRANTY: THE PROGRAM IS PROVIDED TO YOU FREE OF CHARGE AND FOR NO CONSIDERATION AND APTITUNE DISCLAIMS ALL WARRANTIES OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION, ANY WARRANTIES AS TO THE SUITABILITY OF THE PROGRAM FOR YOUR PURPOSES, MERCHANTABILITY, OR FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL APTITUNE BE LIABLE FOR ANY DAMAGES WHATSOEVER, INCLUDING LOSS OF ANTICIPATED PROFITS, OR ANY DIRECT, INCIDENTAL, EXEMPLARY, SPECIAL, OR CONSEQUENTIAL DAMAGES. THE PROGRAM IS PROVIDED TO YOU "AS IS, WHERE IS", AND WITH ALL FAULTS AND WITHOUT ANY WARRANTIES OF ANY KIND. 5. INDEMNIFICATION BY LICENSEE: You agree to indemnify Aptitune from, and hold Aptitune harmless against, any claim or action by any third party arising out of or related to your operation or use of the Program, provided that such indemnification shall not apply to any claim or action by any third party alleging that the Program, as supplied to you by Aptitune, infringes the proprietary rights of any third party. 6. CHOICE OF LAW: This license shall be governed and construed in accordance with the laws of the State of New Hampshire, without giving effect to its conflicts of laws principles, and the Courts of which shall have exclusive jurisdiction over any dispute arising hereunder 7. ACKNOWLEDGMENT: YOU ACKNOWLEDGE THAT YOU HAVE READ THIS AGREEMENT, UNDERSTAND IT, AND AGREE TO BE BOUND BY ITS TERMS AND CONDITIONS. YOU ALSO AGREE THAT THIS AGREEMENT IS THE COMPLETE AND EXCLUSIVE STATEMENT OF AGREEMENT BETWEEN THE PARTIES AND SUPERSEDES ALL PRIOR PROPOSALS, AGREEMENTS, OR UNDERSTANDINGS, WRITTEN OR ORAL, WITH RESPECT TO THE SUBJECT MATTER OF THIS AGREEMENT. Should you have any questions concerning this Agreement, please contact in writing Aptitune Corporation, PO Box 1033, Plaistow NH 03865 USA
Here is freemem. For MSIE, use the right mouse button to click on this link - freemem.tar (30720 bytes) and select "Save Target As". For other browsers, check the documentation. If you're FTPing this file and there's a PC involved, be sure that the PC know that this file is binary and not text.
Interpreting
freemem's output
Here are descriptions of the parameters reported by
freemem:
Signs of memory pressure (in increasing order):
Signs that the system has sufficient memory:
How to graph freemem's output with gnuplot
gnuplot will use the following script will graph the
output of freemem:
set terminal png medium #default set output "/tmp/freemem.png" set title "Free memory on 06/04/2002" "Times-Roman" set xtics rotate set yrange [ 0 : 4000 ] set ylabel "pages of memory" set xlabel " " set xdata time set timefmt "%H:%M:%S" set format x "%H:%M" set size 0.75,0.75 plot "/tmp/fmdata2" using 1:($3) title "freemem" with linespoint 3 ,\ "/tmp/fmdata2" using 1:($7) title "lotsfree" with linespoint 1 ,\ "/tmp/fmdata2" using 1:($5) title "gpgslim" with linespoint 1 reset
Here is the graph produced by gnuplot and it shows that the value of freemem is frequently less than lotsfree, the value of gpgslim is frequently greater than desfree, and the value of freemem is frequently less than gpgslim. The first three conditions to establish the presence of memory pressure have been met. By 10:30, the memory pressure on this system had subsided, and this is apparent because freemem generally stayed above the value of lotsfree and gpgslim always equalled the value of desfree.
Memory pressure can also be confirmed by looking at the size of the dynamic buffer cache. In a graph created with a very similar script, it is apparent that the value of bufpages does not increase beyond that of dbcminpgs until the memory pressure drops. The degree to which bufpages strays from the value of dbcminpgs is determined by memory pressure and the fact that the bufpages line is very flat is typical of systems which do not use the buffer cache heavily.
We hope that you'll find freemem to be a useful tool and we encourage you to distribute it throughout the HP-UX community. And of course, feel free to request an evaluation copy of SarCheck for HP-UX.