Here’s the process I followed to get ImageMagick installed on a CentOS 5 DV Server over at Media Temple. I needed ImageMagick to convert PDFs to JPG files.

1. yum install ImageMagick*
2. pecl install imagick

   Here’s where I encountered the first hiccup:

   shtool at ‘/var/tmp/imagick/build/shtool’ does not exist or is not …

Add the following to your .htaccess file to block posts to wp-comment-posts.php and wp-login.php that have do not have an http referrer or user agent. This will also redirect the user back to their IP address.

<IfModule mod_rewrite.c> 
    RewriteEngine On 
    RewriteCond %{REQUEST_METHOD} POST 
    RewriteCond %{REQUEST_URI} .(wp-comments-post|wp-login)\.php* 
    RewriteCond %{HTTP_REFERER} !.*domain.name.* [OR] …

Reading log files that are from another time zone can add an additional (and unnecessary) layer to your troubleshooting headache. Most of the servers that I touch are on the Eastern seaboard and thus, depending on the earth’s tilt, the offset can vary (thanks UTC!). To resolve this on CentOS, …

The following command is for an Apache setup with multiple vhosts:
tail -f /var/www/vhosts/*/statistics/logs/access_log | grep 'wp-login'

tail -f outputs the end of the log file and updates any new content to the screen as the file is being updated, thus allowing real-time monitoring.

I use this command when fail2ban …