Php session_start generating warning - php

Question

I am trying to run this code in my server
<?php
session_start();
?>
I am getting following warning messages. I never saw such warning before .
Warning: session_start() [function.session-start]: open(/var/chroot/home/content/00/6684400/tmp/sess_uoouukt8m6efc0nc2ar5t2vq94, O_RDWR) failed: No such file or directory (2) in /home/content/00/6684400/html/html-tweetcomments/y.php on line 2
Warning: session_start() [function.session-start]: Cannot send session cookie - headers already sent by (output started at /home/content/00/6684400/html/html-tweetcomments/y.php:2) in /home/content/00/6684400/html/html-tweetcomments/y.php on line 2
Warning: session_start() [function.session-start]: Cannot send session cache limiter - headers already sent (output started at /home/content/00/6684400/html/html-tweetcomments/y.php:2) in /home/content/00/6684400/html/html-tweetcomments/y.php on line 2
Warning: Unknown: open(/var/chroot/home/content/00/6684400/tmp/sess_uoouukt8m6efc0nc2ar5t2vq94, O_RDWR) failed: No such file or directory (2) 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 () in Unknown on line 0
how can i solve this problems?

Answer 1

Make sure, folder /var/chroot/home/content/00/6684400/tmp exists and is writable by PHP
sudo mkdir -p /var/chroot/home/content/00/6684400/tmp/
sudo chmod 1777 /var/chroot/home/content/00/6684400/tmp/
session_start() sets a cookie containing the session id. In the HTTP protocol, Cookies are sent in the HTTP header Set-Cookie.
If you send any output (including PHP warnings), this will be written into the HTTP answer body and PHP is no longer able to send a header.
To make sure the HTTP response body is written at the very end you can add a ob_start() at the very beginning of your PHP script.
This creates a output buffer which will be automatically flushed to output when the script reaches the end.
References
PHP Session
Sticky Bit
HTTP Cookies
PHP ob_start()

Answer 2

Problem with permissions.
Check tmp folder permissions. Make it writable.
Failed to write session data (files).
Also, check there's no HTML or whitespace before session_start()

Answer 3

Warning: session_start() [function.session-start]: Cannot send session
cookie - headers already sent by (output started at
/home/content/00/6684400/html/html-tweetcomments/y.php:2) in
/home/content/00/6684400/html/html-tweetcomments/y.php on line 2
Something is being printed before your session_start call. Check for any echo or even any blank space in html, before your call

Answer 4

The clue is the first error:
open(/var/chroot/home/content/00/6684400/tmp/sess_uoouukt8m6efc0nc2ar5t2vq94, O_RDWR)
failed: No such file or directory (2)
It looks like the directory that is being referenced for the session files either doesn't exist or isn't writable by the web user (user as which the web server is running).
Check that the directory exists - create it if not.
Ensure that it is group writable by the web server user.
The first error is causing the rest of the errors;

Answer 5

If there is same output before php code, move it after the php code
Example:
<script>
...javascript code...
</script>
<?php
session_start();
?>
move the script tag after the php tag. Like this:
<?php
session_start();
?>
<script>
...javascript code...
</script>