---
title: "Magento and Debian default PHP session.gc_probability"
date: "2013-03-14"
path: "/114-magento-and-debian-default-php-session-gc_probability.html"
section: "/ramblings"
aliases:
  - "/114"
  - "/114-magento-and-debian-default-php-session-gc_probability"
  - "/114.html"
  - "/ramblings/114-magento-and-debian-default-php-session-gc_probability.html"
---

We had a discussion a few months back with some of the guys from Magento regards an Enterprise client we had. One of the server recommendations they noted was:

`improper PHP session.gc_probability parameter value (0) on the web server, resulting in automatic session files deletion not working!`

Intrigued by the comment I did some research and found that on Debian Squeeze ([bug 388808](http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=388808) and [321460](http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=321460)) the default is 0 - zero meaning that it will maintain all session files. We even had to make a script that cleared the millions of the session files (see blog listings "[rm: Argument list too long](/43-rm-argument-list-too-long.html)" and "[rm: Argument list too long - improved speed](/44-rm-argument-list-too-long-improved-speed.html)").

Even on some of our existing PHP installs the original, incorrectly set, php.ini rarely gets updated. This results in the following remaining:

`session.gc_probability = 0`

Which should be set as:

`session.gc_probability = 1`