# phpman > man > passenger-memory-stats(8)

[passenger-memory-stats(8)](https://www.chedong.com/phpMan.php/man/passenger-memory-stats/8/markdown)              Administration Commands             [passenger-memory-stats(8)](https://www.chedong.com/phpMan.php/man/passenger-memory-stats/8/markdown)



## NAME
       passenger-memory-stats  -  reports  a  snapshot  of  the  Apache and Phusion Passenger memory
       statistcs

## SYNOPSIS
### passenger-memory-stats

## DESCRIPTION
       **passenger-memory-stats** allows you to easily analyze the real memory usage of Phusion  Passen‐
       ger and Apache.

       Process inspection tools such as _ps_ and _top_ are useful, but they rarely show the correct mem‐
       ory usage. The real memory usage is usually lower than what _ps_ and _top_ report.

       There are many technical reasons why this is so, but an explanation is beyond  the  scope  of
       this  page. We refer the interested reader to operating systems literature about virtual mem‐
       ory and copy-on-write.

       When you run this tool the _Private_ or _private_ _dirty_ _RSS_ field shows the real memory usage  of
       processes.

## ENVIRONMENT VARIABLES
       **HTTPD**  The  full filename to the Apache executable. By default, Passenger will attempt to au‐
              todetect the Apache executable. If  autodetection  fails  for  whatever  reason,  then
              Apache  processes  will  not  be shown in the memory statistics. In that case, you may
              manually specify the location to the Apache executable using  this  environment  vari‐
              able.

## SEE ALSO
       [passenger-status(8)](https://www.chedong.com/phpMan.php/man/passenger-status/8/markdown), [ps(1)](https://www.chedong.com/phpMan.php/man/ps/1/markdown), [top(1)](https://www.chedong.com/phpMan.php/man/top/1/markdown),

       User guide at <https://www.phusionpassenger.com/documentation_and_support>

## AUTHOR
       Phusion Passenger is written by Phusion (<http://www.phusion.nl>)

       This  manual  page  was  written by Neil Wilson <<neil@brightbox.co.uk>> for the Ubuntu project
       (but may be used by others).



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