Thanks @nas and @stephdl for pointing this out! I agree we need to fix this value.
Each application could define its session storage method. I think the best place to set session.save_path is into an application configuration file (for instance, server-manager assumes /var/cache/nethserver-httpd-admin), so it can be different for each application.
Moreover, PHP does not set a default, because the path depends on the platform. Our platform is CentOS, and php-common sets the default to /var/lib/php/session, in php.ini.
I propose to set the default to the value chosen by upstream.
There are also a lot of other parameters that could be adjusted to reflect the upstream settings. For ns7 I'd like to be more upstream-compliant and revert the php.ini to the upstream version. Our template can be moved to an included file, like /etc/php.d/nethserver.ini. What do you think?
These are the differences from upstream: