Currently your messages log is filling up with errors and the system is unstable. Check the message log:

$ server# tail -f /var/log/messages
Jul 28 08:57:30 mail kernel: EXT4-fs warning (device sda3): ext4_dx_add_entry: Directory index full!

Check the sessions directory

 $ server# php -i | grep session.save_path
session.save_path => /var/lib/php/session => /var/lib/php/session

$ server# du -shcx /var/lib/php/session
1000.0M    /var/lib/php/session
1000.0M    total

A cron job similar to the following ran every day, or periodically, should prevent those files from accumulating.

# find /var/lib/php/session -type d -mtime -15 -delete


# find /var/lib/php/session -depth -mindepth 1 -maxdepth 1 -type f -cmin +120 -delete;

Find file owned by a group

find directory-location -group {group-name} -name {file-name}

directory-location : directory path.
-group {group-name} : group-name.
-name {file-name} : The file name or a search pattern

Issue: Plesk server will not allow updating plugins and the site is running as fastcgi – which uses the ftp user as the root user ( coldriverw:psacln) is the user:group for this account.

In this example, locate or find all files belongs to a group called “apache” in the /var/www/vhosts/ directory:

[root@austin plugins]# find /var/www/vhosts/ -group apache

Change the files to the correct user:

 [root@austin plugins]# chown -R domain:psacln /var/www/vhosts/

Retry the wordpress upload

Update Plugin
Downloading update from…

Unpacking the update…

Installing the latest version…

Removing the old version of the plugin…

Plugin updated successfully.

More information:

For directories

[root@server]# find /var/www/vhosts/ -type d -perm 777 -print

Set to 755:

root@server ]# find /var/www/vhosts/ -type d -perm 777 -exec chmod 755 {} \;

For Files

[root@server]# find /var/www/vhosts/ -type f -perm 777 -print

Set to 644:

[root@server]# find /var/www/vhosts/ -type f -perm 777 -exec chmod 644 {} \;