Symfony app writing config files to tmp directory

I've inherited an old Symfony app (Symfony 1.4) and had to migrate it to a new server. I have no experience with Symfony, but the migration went well and everything works fine except one thing; the new server's admin(s) complain about the app writing files to /tmp directory every minute:

Partial sample output from admins:

-rw-------  1 www-data  www-data      17133 Dec 18 14:45 config_routing.yml.php4VSPbj
-rw-------  1 www-data  www-data      17133 Dec 18 14:47 config_routing.yml.php8ZZlxn
-rw-------  1 www-data  www-data      17133 Dec 18 14:38 config_routing.yml.php9NH03d
-rw-------  1 www-data  www-data      17133 Dec 18 14:38 config_routing.yml.phpGA9YrM
-rw-------  1 www-data  www-data      17133 Dec 18 14:45 config_routing.yml.phpO9fYz5
-rw-------  1 www-data  www-data      17133 Dec 18 14:47 config_routing.yml.phpOiXAYC
-rw-------  1 www-data  www-data      17133 Dec 18 14:43 config_routing.yml.phpptNyFw

and these files as well:

config_settings.yml.php, config_databases.yml.php, config_autoload.yml.php.

I've made sure debugging is disabled in prod environment, but this still happens. Does anyone have any clue to what might be causing this?

Solution

It seems the applications cache directory does not exists, tempnam() function used by sfConfigCache class then defaults to using system temp directory.

The default location is ./cache, create it and make it writable by apache.

To understand what is happening, snippets from sfConfigCache class:

Line 344: $tmpFile = tempnam(dirname($cache), basename($cache)); Here the /tmp/config_routing.yml.php* files are created, to be renamed or copied few lines later:

if (!@rename($tmpFile, $cache))
{
  if (copy($tmpFile, $cache))
  {
    unlink($tmpFile);
  }
}

Obviously, both rename and copy failed.