ini_set('memory_limit', …) doesn't work and returns false; can't figure out why

Question

ini_set('memory_limit', '128M'); // Returns false; memory_limit unchanged

I wasn't able to find a list of things that can cause this. So far I checked:

• Safe mode: disabled
• disable_functions: Empty
• php_admin_value: None that I could find (is there a way to know for sure?)

I ran out of ideas! ini_set works correctly with other parameters (such as "display_errors")

Answer 1

If it's not the PHP version problem posted already try checking that there's nothing on the machine preventing your from raising this limit.

How to check whether Suhosin is installed?

edit (after establishing that Suhosin is installed):

Config details are here: http://www.hardened-php.net/suhosin/configuration.html I suspect there'll be a file in /etc/php.d/ that you can edit to increase the memory limit bounds. The config variable you need to edit is: suhosin.memory_limit

Answer 2

The manual says :

Prior to PHP 5.2.1, in order to use this directive it had to be enabled at compile time by using --enable-memory-limit in the configure line

That might be the cause of your problem.