php-fpm and nginx session problems

I’ve been having this problem for the past week or so. I’ve been working on a PHP project that relies HEAVILY on Sessions. For some reason we’ve been having troubles with the sessions saving the past few days. Any idea why?

Here’s the error:

Warning: Unknown: open(/tmp/sess_mmd0ru5pl2h2h9bummcu1uu620, O_RDWR) failed: Permission denied (13) in Unknown on line 0 Warning: Unknown: Failed to write session data (files). Please verify that the current setting of session.save_path is correct (/tmp) in Unknown on line 0
Warning: session_start(): open(/tmp/sess_mmd0ru5pl2h2h9bummcu1uu620, O_RDWR) failed: Permission denied (13)

nginx version:

nginx version: nginx/1.0.11

PHP-FPM config:

;;;;;;;;;;;;;;;;;;;;;
; FPM Configuration ;
;;;;;;;;;;;;;;;;;;;;;

; All relative paths in this configuration file are relative to PHP's install
; prefix.

; Include one or more files. If glob(3) exists, it is used to include a bunch of
; files from a glob(3) pattern. This directive can be used everywhere in the
; file.
include=/etc/php-fpm.d/*.conf

;;;;;;;;;;;;;;;;;;
; Global Options ;
;;;;;;;;;;;;;;;;;;

[global]
; Pid file
; Default Value: none
pid = /var/run/php-fpm/php-fpm.pid

; Error log file
; Default Value: /var/log/php-fpm.log
error_log = /var/log/php-fpm/error.log

; Log level
; Possible Values: alert, error, warning, notice, debug
; Default Value: notice
;log_level = notice

; If this number of child processes exit with SIGSEGV or SIGBUS within the time
; interval set by emergency_restart_interval then FPM will restart. A value
; of '0' means 'Off'.
; Default Value: 0
;emergency_restart_threshold = 0

; Interval of time used by emergency_restart_interval to determine when
; a graceful restart will be initiated.  This can be useful to work around
; accidental corruptions in an accelerator's shared memory.
; Available Units: s(econds), m(inutes), h(ours), or d(ays)
; Default Unit: seconds
; Default Value: 0
;emergency_restart_interval = 0

; Time limit for child processes to wait for a reaction on signals from master.
; Available units: s(econds), m(inutes), h(ours), or d(ays)
; Default Unit: seconds
; Default Value: 0
;process_control_timeout = 0

; Send FPM to background. Set to 'no' to keep FPM in foreground for debugging.
; Default Value: yes
;daemonize = yes

;;;;;;;;;;;;;;;;;;;;
; Pool Definitions ;
;;;;;;;;;;;;;;;;;;;;

; See /etc/php-fpm.d/*.conf

nginx.conf:

#######################################################################
#
# This is the main Nginx configuration file.
#
# More information about the configuration options is available on
#   * the English wiki - http://wiki.nginx.org/Main
#   * the Russian documentation - http://sysoev.ru/nginx/
#
#######################################################################

#----------------------------------------------------------------------
# Main Module - directives that cover basic functionality
#
#   http://wiki.nginx.org/NginxHttpMainModule
#
#----------------------------------------------------------------------

user              nginx nginx;
worker_processes  5;

error_log  /var/log/nginx/error.log;
#error_log  /var/log/nginx/error.log  notice;
#error_log  /var/log/nginx/error.log  info;

pid        /var/run/nginx.pid;


#----------------------------------------------------------------------
# Events Module
#
#   http://wiki.nginx.org/NginxHttpEventsModule
#
#----------------------------------------------------------------------

events {
    worker_connections  4096;
}


#----------------------------------------------------------------------
# HTTP Core Module
#
#   http://wiki.nginx.org/NginxHttpCoreModule
#
#----------------------------------------------------------------------

http {
    include       /etc/nginx/mime.types;
    default_type  application/octet-stream;

    log_format  main  '$remote_addr - $remote_user [$time_local] "$request" '
                      '$status $body_bytes_sent "$http_referer" '
                      '"$http_user_agent" "$http_x_forwarded_for"';

    access_log  /var/log/nginx/access.log  main;

        index index.php index.html index.htm;

    sendfile        on;
    #tcp_nopush     on;

    #keepalive_timeout  0;
    keepalive_timeout  65;

    #gzip  on;

    # Load config files from the /etc/nginx/conf.d directory
    # The default server is in conf.d/default.conf
    include /etc/nginx/conf.d/*.conf;
        server {
                listen 80;
                server_name stats.smilingdevil.com;

                error_page   404   /404.php;

                root /var/www;

                access_log /var/log/nginx/access.log;
                error_log /var/log/nginx/error.log;

                location / {
                        set $page_to_view "/index.php";
                        try_files $uri $uri/ @rewrites;
                        root /var/www/;
                        index index.php;
                }

                location @rewrites {
                        if ($uri ~* ^/([a-z0-9]+)$) {
                                set $page_to_view "/$1.php";
                                rewrite ^/([a-z]+)$ /$1.php last;
                        }
                }

                location ~ .php$ {
                        include /etc/nginx/fastcgi.conf;
                        fastcgi_pass 127.0.0.1:9000;
                        fastcgi_param SCRIPT_FILENAME /var/www$fastcgi_script_name;
                }
        }
}

Answer

I found that my php.ini was attempting to save sessions to /var/lib/php/session rather than /tmp

So check your ini file and see where they’re being saved to (or set it to somewhere else); then make sure that directory is writeable by the appropriate processes