Configuration Notes and Tips

Table of Contents

SELinux

See the SELinux Configuration Guide for a suggested configuration for SELinux-enabled distributions such as Fedora and CentOS.

php.ini

Several core PHP settings must be configured correctly, otherwise ownCloud may not work properly. Known settings causing issues are listed here. Please note that, there might be other settings which cause unwanted behavior. In general, however, it is recommended to keep the php.ini settings at their defaults, except when you know exactly why the change is required, and its implications.

Keep in mind that, changes to php.ini may have to be configured in more than one ini file. This can be the case, for example, for the date.timezone setting.

php.ini - Used by the Web server

For PHP version 7.4.0 onward, replace php_version with the version number installed, e.g., 7.4 in the following examples.

/etc/php/[php_version]/apache2/php.ini

or

/etc/php/[php_version]/fpm/php.ini

or

php.ini - used by the php-cli and so by ownCloud CRON jobs

/etc/php/[php_version]/cli/php.ini

session.auto_start && enable_post_data_reading

Ensure that session.auto_start is set to 0 or Off and enable_post_data_reading to 1 or On in your configuration. If not, you may have issues logging in to ownCloud via the WebUI, where you see the error: "Access denied. CSRF check failed".

session.save_path

In addition to setting session.auto_start and enable_post_data_reading correctly, ensure that, if session.save_handler is set to files, that session.save_path is set to a path on the filesystem which only the web server process (or process which PHP is running as) can read from and write to.

This is especially important if your ownCloud installation is using a shared-hosting arrangement. In these situations, session poisoning can occur if all of the session files are stored in the same location. Session poisoning is where one web application can manipulate data in the $_SESSION superglobal array of another.

When this happens, the original application has no way of knowing that this corruption has occurred and may not treat the data with any sense of suspicion. You can read through a thorough discussion of local session poisoning if you’d like to know more.

post_max_size

Please ensure that you have post_max_size configured with at least the minimum amount of memory for use with ownCloud, which is 512 MB.

Please be careful when you set this value if you use the byte value shortcut as it is very specific. Use K for kilobyte, M for megabyte and G for gigabyte. KB, MB, and GB do not work!

realpath_cache_size

This determines the size of the realpath cache used by PHP. This value should be increased on systems where PHP opens many files, to reflect the number of file operations performed. For a detailed description see realpath-cache-size. This setting has been available since PHP 5.1.0. Prior to PHP 7.0.16 and 7.1.2, the default was 16 KB.

To see your current value, query your phpinfo() output for this key. It is recommended to set the value if it is currently set to the default of 16 KB. A good reading about the background can be found at tideways.io.

How to get a working value

With the assumption of 112 bytes per file path needed, this would allow the cache to hold around 37.000 items with a cache size of 4096K (4M), but only about a hundred entries for a cache size of 16 KB.

It’s a good rule of thumb to always have a realpath cache that can hold entries for all your files paths in memory. If you use symlink deployment, then set it to double or triple the amount of files.

The easiest way to get the quantity of PHP files is to use cloc, which can be installed by running sudo apt-get install cloc. The cloc package is available for nearly all distributions.

sudo cloc /var/www/owncloud --exclude-dir=data --follow-links
   12179 text files.
   11367 unique files.
   73126 files ignored.
http://cloc.sourceforge.net v 1.60  T=1308.98 s (6.4 files/s, 1283.5 lines/s)
--------------------------------------------------------------------------------
Language                      files          blank        comment           code
--------------------------------------------------------------------------------
PHP                            4896          96509         285384         558135
...

Taking the math from above and assuming a symlinked instance, using factor 3. For example: 4896 * 3 * 112 = 1.6MB This result shows that you can run with the PHP setting of 4M two instances of ownCloud.

Having the default of 16 KB means that only 1/100 of the existing PHP file paths can be cached and need continuous cache refresh slowing down performance. If you run more web services using PHP, you have to calculate accordingly.

PHP-FPM

Note that mod_php is used exclusively in the development and QA process of the ownCloud server. It’s highly recommended to use mod_php in your production environment for optimal performance and stability. Any issues with the ownCloud server have to be reproducible with mod_php.

SAML SSO with Shibboleth will not work with php-fpm.

System Environment Variables

When you are using php-fpm, system environment variables like PATH, TMP or others are not automatically populated in the same way as when using php-cli. A PHP call like getenv('PATH'); can therefore return an empty result. So you may need to manually configure environment variables in the appropriate php-fpm ini/config file.

Here are some example root paths for these ini/config files:

Ubuntu/Mint

CentOS/Red Hat/Fedora

/etc/php/[php_version]/fpm/

/etc/php-fpm.d/

In both examples, the ini/config file is called www.conf, and depending on the distribution or customizations which you have made, it may be in a sub-directory.

Usually, you will find some or all of the environment variables already in the file, but commented out like this:

;env[HOSTNAME] = $HOSTNAME
;env[PATH] = /usr/local/bin:/usr/bin:/bin
;env[TMP] = /tmp
;env[TMPDIR] = /tmp
;env[TEMP] = /tmp

Uncomment the appropriate existing entries. Then run printenv PATH to confirm your paths, for example:

printenv PATH
/home/user/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:
/sbin:/bin:/

If any of your system environment variables are not present in the file then you must add them.

When you are using shared hosting or a control panel to manage your ownCloud virtual machine or server, the configuration files are almost certain to be located somewhere else, for security and flexibility reasons, so check your documentation for the correct locations.

Please keep in mind that it is possible to create different settings for php-cli and php-fpm, and for different domains and Web sites. The best way to check your settings is with label-phpinfo.

Maximum Upload Size

If you want to increase the maximum upload size, you will also have to modify your php-fpm configuration and increase the upload_max_filesize and post_max_size values. You will need to restart php5-fpm and your HTTP server in order for these changes to be applied.

.htaccess Notes for Apache

ownCloud comes with its own owncloud/.htaccess file. Because php-fpm can’t read PHP settings in .htaccess these settings and permissions must be set in the owncloud/.user.ini file.

No basic authentication headers were found

This error is shown in your data/owncloud.log file. Some Apache modules like mod_fastcgi, mod_fcgid or mod_proxy_fcgi are not passing the needed authentication headers to PHP and so the login to ownCloud via WebDAV, CalDAV and CardDAV clients is failing. Information on how to correctly configure your environment can be found in the forums but we generally recommend not to use these modules and recommend mod_php instead.