When WordPress installs plug-ins or updates, it will prompt that the directory creation fails

Enter the WordPress working directory, use the ls-l command to view the file details in the WordPress working directory, and you can see the working group.

[root@host wordpress]# ls -l
total 196
-rw-r--r--  1 root root   418 Oct  9 10:35 index.php
-rwxrwxrwx  1 root root 19935 Oct  9 10:46 license.txt
-rwxrwxrwx  1 root root  7415 Oct  9 10:46 readme.html
-rwxr-xr-x  1 root root  5458 Oct  9 10:35 wp-activate.php
drwxr-xr-t  9 root root  4096 Oct  8 19:43 wp-admin
-rw-r--r--  1 root root   364 Oct  9 10:35 wp-blog-header.php
-rw-r--r--  1 root root  1889 Oct  9 10:35 wp-comments-post.php
-rw-r--r--  1 root root  3294 Oct  8 19:43 wp-config.php
-rwxr-xr-x  1 root root  2853 Oct  9 10:35 wp-config-sample.php
drwxr-xr-t  6 root root  4096 Oct  8 19:43 wp-content
-rw-r--r--  1 root root  3669 Oct  9 10:35 wp-cron.php
drwxr-xr-t 18 root root 12288 Oct  8 19:43 wp-includes
-rw-r--r--  1 root root  2422 Oct  9 10:35 wp-links-opml.php
-rw-r--r--  1 root root  3306 Oct  9 10:35 wp-load.php
-rwxr-xr-x  1 root root 37794 Oct  9 10:35 wp-login.php
-rw-r--r--  1 root root  8048 Oct  9 10:35 wp-mail.php
-rw-r--r--  1 root root 16246 Oct  9 10:35 wp-settings.php
-rw-r--r--  1 root root 30091 Oct  9 10:35 wp-signup.php
-rw-r--r--  1 root root  4620 Oct  9 10:35 wp-trackback.php
-rw-r--r--  1 root root  3065 Oct  9 10:35 xmlrpc.php

As you can see above, they are in the root working group, and we need to update the download operation in the Web group, namely the user group www.
Modify it below

[root@host wordpress]# chown -R www:www ./

Then view the user group again

[root@host wordpress]# ls -l
total 196
-rw-r--r--  1 www www   418 Oct  9 10:35 index.php
-rwxrwxrwx  1 www www 19935 Oct  9 10:46 license.txt
-rwxrwxrwx  1 www www  7415 Oct  9 10:46 readme.html
-rwxr-xr-x  1 www www  5458 Oct  9 10:35 wp-activate.php
drwxr-xr-t  9 www www  4096 Oct  8 19:43 wp-admin
-rw-r--r--  1 www www   364 Oct  9 10:35 wp-blog-header.php
-rw-r--r--  1 www www  1889 Oct  9 10:35 wp-comments-post.php
-rw-r--r--  1 www www  3294 Oct  8 19:43 wp-config.php
-rwxr-xr-x  1 www www  2853 Oct  9 10:35 wp-config-sample.php
drwxr-xr-t  6 www www  4096 Oct  8 19:43 wp-content
-rw-r--r--  1 www www  3669 Oct  9 10:35 wp-cron.php
drwxr-xr-t 18 www www 12288 Oct  8 19:43 wp-includes
-rw-r--r--  1 www www  2422 Oct  9 10:35 wp-links-opml.php
-rw-r--r--  1 www www  3306 Oct  9 10:35 wp-load.php
-rwxr-xr-x  1 www www 37794 Oct  9 10:35 wp-login.php
-rw-r--r--  1 www www  8048 Oct  9 10:35 wp-mail.php
-rw-r--r--  1 www www 16246 Oct  9 10:35 wp-settings.php
-rw-r--r--  1 www www 30091 Oct  9 10:35 wp-signup.php
-rw-r--r--  1 www www  4620 Oct  9 10:35 wp-trackback.php
-rw-r--r--  1 www www  3065 Oct  9 10:35 xmlrpc.php

When WordPress is updated, it succeeds