Cannot install plugins on Centos VPS

Question

I am unable to install plugins on my Centos 6 VPS. When I attempt the install I get this:

Installing Plugin: BotDetect WordPress CAPTCHA 3.0.Beta1.7

Downloading install package from
[web path to:]botdetect-wp-captcha.zip…
Unpacking the package…
Could not create directory.
Return to Plugin Installer

UPDATE: This seems to have something to do with permissions -- I'm guessing there's some group that wordpress needs to be part of in order to change folders, create files, etc., but I can't figure out what that group should be. I have no www-data group -- I read something somewhere about this being a requirement. Can somebody tell me what groups and permissions need to exist for WP to operate?

UPDATE: I have chmodded the permissions to my plugin and uploads folders to 777. I also have created an FTP user specifically for Wordpress and made the home directory for that user the same as my Wordpress root folder as recommended HERE. I then changed these lines in the wp-config.php file from:

/** Absolute path to the WordPress directory. */
if ( !defined('ABSPATH') )
    define('ABSPATH', dirname(__FILE__ . "/"));

/** Sets up WordPress vars and included files. */
require_once(ABSPATH . 'wp-settings.php');

to:

/** Absolute path to the WordPress directory. */
if ( !defined('ABSPATH') )
    define('ABSPATH', dirname(__FILE__));

/** Sets up WordPress vars and included files. */
require_once(ABSPATH . '/wp-settings.php');

This should eliminate the double slash conflict mentioned HERE.

Note -- I was also having a problem uploading media but that issues was resolved with the chmod to 777.

Now when I try to install a plugin I get this:

Unable to locate WordPress Plugin directory.

Return to Plugin Installer

Answer 1

Okay, I figured this out based upon suggestions from StackOverflow. This is how I resolved this issue:

I created a group called ftpusers.

groupadd ftpusers

I added my wordpress user to this group.

usermod -a -G ftpusers wordpressuser

I changed ownership of the wordpress folder recursively to my wordpress user:group.

chown -R wordpressuser:ftpusers wordpress

Voila -- my package installed.

Answer 2

This problem doesn't seem to be regarding CentOS but the permissions of your folders. Try creating the plugins folder in your wp-content. If that doesn't work try CHMODDING 755 or 777 (though this may be risky, try just for testing purposes) on the newly creating plugins folder.