php Fatal error: session_start(): Failed to initialize stora_PHP教程

Today, when calling session in PHP, Fatal error: session_start(): Failed to initialize storage module: files(session.inc.php on line 83) was prompted. Let me share with you how to deal with this problem.

Original solution: Fatal error: session_start(): Failed to initialize storage module: files problem

The LNMP environment + phpmyamdin4.02 version that was compiled and installed before suddenly appeared this problem today:
Fatal error: session_start(): Failed to initialize storage module: files (path: ) in /data/www/phpmyadmin/libraries/session.inc.php on line 83
The general meaning is that the storage path is wrong when the session is initialized! The first reaction is to check the configuration file of php.ini:

By default, there is a semicolon in front of it, which means it is not enabled. It was already enabled when I configured it before. So why does it still report an error? , so I looked for some information on the Internet, and I felt that they were all the same:
1. Check the error.log (Apache2.2logs) file to see if there is an error report. Not found.

2. Check whether the value of session.save_handler in php.ini is files, if not, change it to files

3. Check whether session.save_path is commented in the php.ini file. If so, remove the preceding ";".

4. Change the path after save_path to an existing path, such as "D:phptemp"

5. Check whether the attributes of the temp folder are readable and writable.

6. Restart the APACHE server. OK
I don’t know if those guys have tried it themselves when they reprinted it (I’m going to spray it here, I hate it the most without even testing it myself, so I just circulate it around. It’s not responsible at all!)
According to the above process, after troubleshooting, it was found that there was no solution at all, but Puyu's server was nginx, not apache.
Then I wrote a script test.php:
$r = session_start(); var_dump($r);
The print result is:
Warning: session_start(): SAFE MODE Restriction in effect. The script whose uid is 501 is not allowed to access /tmp owned by uid 0 in /data/www/test.php on line 3 Fatal error: session_start(): Failed to initialize storage module: files (path: ) in /data/www/test.php on line 3
It means that there is a bug in the safe mode of php5. The default save_path of the session is the temporary directory of the system, which will require verification of permissions. And this script cannot be executed through the /tmp owner uid is 0. The uid is 501 and it is also the permission of the www user group
There are two solutions to this problem:
1. Turn off safe mode;

2. Change the owner of a file/directory by chowning on the command line

Of course both methods require you to have server permissions.

下面是璞玉php.ini的配置文件：
[Session]
 ; Handler used to store/retrieve data.
 ; http://php.net/session.save-handler
session.save_handler = files; Argument passed to save_handler.  In the case of files, this is the path
 ; where data files are stored. Note: Windows users have to change this
 ; variable in order to use PHP's session functions.
 ;
 ; The path can be defined as:
 ;
 ;     session.save_path = "N;/path"
 ;
 ; where N is an integer.  Instead of storing all the session files in
 ; /path, what this will do is use subdirectories N-levels deep, and
 ; store the session data in those directories.  This is useful if you
 ; or your OS have problems with lots of files in one directory, and is
 ; a more efficient layout for servers that handle lots of sessions.
 ;
 ; NOTE 1: PHP will not create this directory structure automatically.
 ;         You can use the script in the ext/session dir for that purpose.
 ; NOTE 2: See the section on garbage collection below if you choose to
 ;         use subdirectories for session storage
 ;
 ; The file storage module creates files using mode 600 by default.
 ; You can change that by using
 ;
 ;     session.save_path = "N;MODE;/path"
 ;
 ; where MODE is the octal representation of the mode. Note that this
 ; does not overwrite the process's umask.
 ; http://php.net/session.save-path
 session.save_path = "/tmp"
; Whether to use cookies.
 ; http://php.net/session.use-cookies
 session.use_cookies = 1
; http://php.net/session.cookie-secure
 ;session.cookie_secure =
; This option forces PHP to fetch and use a cookie for storing and maintaining
 ; the session id. We encourage this operation as it's very helpful in combatting
 ; session hijacking when not specifying and managing your own session id. It is
 ; not the end all be all of session hijacking defense, but it's a good start.
 ; http://php.net/session.use-only-cookies
 session.use_only_cookies = 1
; Name of the session (used as cookie name).
 ; http://php.net/session.name
 session.name = PHPSESSID
; Initialize session on request startup.
 ; http://php.net/session.auto-start
 session.auto_start = 0
; Lifetime in seconds of cookie or, if 0, until browser is restarted.
 ; http://php.net/session.cookie-lifetime
 session.cookie_lifetime = 0
; The path for which the cookie is valid.
 ; http://php.net/session.cookie-path
 session.cookie_path = /
; The domain for which the cookie is valid.
 ; http://php.net/session.cookie-domain
 session.cookie_domain =
; Whether or not to add the httpOnly flag to the cookie, which makes it inaccessible to browser scripting languages such as JavaScript.
 ; http://php.net/session.cookie-httponly
 session.cookie_httponly =
; Handler used to serialize data.  php is the standard serializer of PHP.
 ; http://php.net/session.serialize-handler
 session.serialize_handler = php
; Defines the probability that the 'garbage collection' process is started
 ; on every session initialization. The probability is calculated by using
 ; gc_probability/gc_divisor. Where session.gc_probability is the numerator
 ; and gc_divisor is the denominator in the equation. Setting this value to 1
 ; when the session.gc_divisor value is 100 will give you approximately a 1% chance
 ; the gc will run on any give request.
 ; Default Value: 1
 ; Development Value: 1
 ; Production Value: 1
 ; http://php.net/session.gc-probability
 session.gc_probability = 1
; Defines the probability that the 'garbage collection' process is started on every
 ; session initialization. The probability is calculated by using the following equation:
 ; gc_probability/gc_divisor. Where session.gc_probability is the numerator and
 ; session.gc_divisor is the denominator in the equation. Setting this value to 1
 ; when the session.gc_divisor value is 100 will give you approximately a 1% chance
 ; the gc will run on any give request. Increasing this value to 1000 will give you
 ; a 0.1% chance the gc will run on any give request. For high volume production servers,
 ; this is a more efficient approach.
 ; Default Value: 100
 ; Development Value: 1000
 ; Production Value: 1000
 ; http://php.net/session.gc-divisor
 session.gc_divisor = 1000
; After this number of seconds, stored data will be seen as 'garbage' and
 ; cleaned up by the garbage collection process.
 ; http://php.net/session.gc-maxlifetime
 session.gc_maxlifetime = 1440
; NOTE: If you are using the subdirectory option for storing session files
 ;       (see session.save_path above), then garbage collection does *not*
 ;       happen automatically.  You will need to do your own garbage
 ;       collection through a shell script, cron entry, or some other method.
 ;       For example, the following script would is the equivalent of
 ;       setting session.gc_maxlifetime to 1440 (1440 seconds = 24 minutes):
 ;          find /path/to/sessions -cmin +24 | xargs rm
; PHP 4.2 and less have an undocumented feature/bug that allows you to
 ; to initialize a session variable in the global scope, even when register_globals
 ; is disabled.  PHP 4.3 and later will warn you, if this feature is used.
 ; You can disable the feature and the warning separately. At this time,
 ; the warning is only displayed, if bug_compat_42 is enabled. This feature
 ; introduces some serious security problems if not handled correctly. It's
 ; recommended that you do not use this feature on production servers. But you
 ; should enable this on development servers and enable the warning as well. If you
 ; do not enable the feature on development servers, you won't be warned when it's
 ; used and debugging errors caused by this can be difficult to track down.
 ; Default Value: On
 ; Development Value: On
 ; Production Value: Off
 ; http://php.net/session.bug-compat-42
 session.bug_compat_42 = Off
; This setting controls whether or not you are warned by PHP when initializing a
 ; session value into the global space. session.bug_compat_42 must be enabled before
 ; these warnings can be issued by PHP. See the directive above for more information.
 ; Default Value: On
 ; Development Value: On
 ; Production Value: Off
 ; http://php.net/session.bug-compat-warn
 session.bug_compat_warn = Off
; Check HTTP Referer to invalidate externally stored URLs containing ids.
 ; HTTP_REFERER has to contain this substring for the session to be
 ; considered as valid.
 ; http://php.net/session.referer-check
 session.referer_check =
; How many bytes to read from the file.
 ; http://php.net/session.entropy-length
 session.entropy_length = 0
; Specified here to create the session id.
 ; http://php.net/session.entropy-file
 ; On systems that don't have /dev/urandom /dev/arandom can be used
 ; On windows, setting the entropy_length setting will activate the
 ; Windows random source (using the CryptoAPI)
 ;session.entropy_file = /dev/urandom
; Set to {nocache,private,public,} to determine HTTP caching aspects
 ; or leave this empty to avoid sending anti-caching headers.
 ; http://php.net/session.cache-limiter
 session.cache_limiter = nocache
; Document expires after n minutes.
 ; http://php.net/session.cache-expire
 session.cache_expire = 180
; trans sid support is disabled by default.
 ; Use of trans sid may risk your users security.
 ; Use this option with caution.
 ; - User may send URL contains active session ID
 ;   to other person via. email/irc/etc.
 ; - URL that contains active session ID may be stored
 ;   in publically accessible computer.
 ; - User may access your site with the same session ID
 ;   always using URL stored in browser's history or bookmarks.
 ; http://php.net/session.use-trans-sid
 session.use_trans_sid = 0
; Select a hash function for use in generating session ids.
 ; Possible Values
 ;   0  (MD5 128 bits)
 ;   1  (SHA-1 160 bits)
 ; This option may also be set to the name of any hash function supported by
 ; the hash extension. A list of available hashes is returned by the hash_algos()
 ; function.
 ; http://php.net/session.hash-function
 session.hash_function = 0
; Define how many bits are stored in each character when converting
 ; the binary hash data to something readable.
 ; Possible values:
 ;   4  (4 bits: 0-9, a-f)
 ;   5  (5 bits: 0-9, a-v)
 ;   6  (6 bits: 0-9, a-z, A-Z, "-", ",")
 ; Default Value: 4
 ; Development Value: 5
 ; Production Value: 5
 ; http://php.net/session.hash-bits-per-character
 session.hash_bits_per_character = 5
; The URL rewriter will look for URLs in a defined set of HTML tags.
 ; form/fieldset are special; if you include them here, the rewriter will
 ; add a hidden field with the info which is otherwise appended
 ; to URLs.  If you want XHTML conformity, remove the form entry.
 ; Note that all valid entries require a "=", even if no value follows.
 ; Default Value: "a=href,area=href,frame=src,form=,fieldset="
 ; Development Value: "a=href,area=href,frame=src,input=src,form=fakeentry"
 ; Production Value: "a=href,area=href,frame=src,input=src,form=fakeentry"
 ; http://php.net/url-rewriter.tags
 url_rewriter.tags = "a=href,area=href,frame=src,input=src,form=fakeentry"因为这个是在一台VPS上面配置的，上面有多个项目，于是璞玉打开一个项目，发现此项目的验证码功能是OK的。
于是查看代码如下：