/var/lib/php/session cleanup failing

We found one of our servers had exceeded the inode limit of 400,000. Upon investigation, there were about 250,000 files in /var/lib/php/session

The script plesk-php-cleanuper contains a string ! -execdir fuser {} \, which opens every file in the /var/lib/php/session directory and checks that it is not used by a working process and can be deleted. However, the maximum number of open files is set to 1024 by default.

Clear /var/lib/php/session using this script without the checker:
~# [ -x /usr/lib64/plesk-9.0/maxlifetime ] && [ -d /var/lib/php/session ] && find /var/lib/php/session -depth -mindepth 1 -maxdepth 1 -type f -cmin +$(/usr/lib64/plesk-9.0/maxlifetime) -delete
Increase the limit for open files to the required value.
To get the maximum number of open files, run:
~# ulimit -a
open files (-n) 1024
Add ulimit -n 30480 to /etc/cron.hourly/plesk-php-cleanuper:
~#vi /etc/cron.hourly/plesk-php-cleanuper
~ulimit -n 30480

Re-run the required Cron Job and check that it completes successfully .


wordpress – plesk error Call to undefined function is_admin()

In the Plesk under the subscription we are seeing the following error and we can not apply the Plesk security settings. 

Error: PHP Fatal error: Call to undefined function is_admin() in /usr/share/plesk-wp-cli/php/wp-cli.php(18) : eval()’d code on line 87

Parallels identifies this in a KB article:


They say:


Modified wp-config.php file inside a WordPress installation document root. Function is_admin() could be handled properly while it evaluated from CLI.


Either remove his function from the wp-config.php or modify it, as it shown on example below:


We compared the config against another new installation and removed the following lines from it.


if(is_admin()) {

    add_filter(‘filesystem_method’, create_function(‘$a’, ‘return “direct”;’ ));

    define( ‘FS_CHMOD_DIR’, 0751 );


if(is_admin()) {

    add_filter(‘filesystem_method’, create_function(‘$a’, ‘return “ftpext”;’ ));

    define( ‘FS_CHMOD_DIR’, 0755 );



Then in the subscriptions control panel we clicked the Plesk to refresh button for WordPress security scan and all appears to be fine now.

WordPress migration with full Plesk integration

Step by step instructions for moving a WordPress site between servers using ‘duplicator’ plugin.

Source server
1. Install duplicator
Login to WP admin area. Click Plugins. Search for ‘Duplicator’ plugin and install.
2. Activate the plugin through the ‘Plugins’ menu in WordPress
3. Click on the Duplicator link from the main menu
4. Create your first package.
You will go through a verification check of the setup. Fix any issues that duplicator finds.
5. FTP installer.php and packageName_archive.zip to destination server (download to PC, upload to new server).

Destination server
1. Move installer.php and package.zip file into document root directory.
2. Install WP through Plesk. This step is only necessary if you want Plesk to recognize the WP installation.
3. Look in the wp-config.php file and make a note of mysql db, user, password and then rename file to be wp-config.php.back.
4. Run the installer.php script. Adjust domain name and mysql settings.
5. Verify successful migration.
6. Remove migration files: installer.php, installer-data.sql, installer-log.txt, packageName_archive.zip, wp-config.php.back