Racker Hacker Words of wisdom from a server administrator

Sticky bits help you take file permissions to the next level. Here’s an example of a situation where sticky bits help:
Let’s say you have a directory on a server called “share”. For this directory, you have 3 users: adam, bill, and carl. You are the administrator, so you want to create a [...]

If you find yourself in the sticky situation where kill -9 still won’t kill a sendmail process, check the process list. If ps fax returns a “D” status code, you won’t be able to stop the process. It’s in an “uninterruptable sleep” state which cannot be killed.
What can you do to fix this? [...]

In the event that a Fedora/RHEL/CentOS box won’t perform the init (which comes right after the initial kernel load), don’t fret – it can be fixed. Make a note of the missing libraries or executables. Simply boot onto a livecd or rescuecd and chroot into your main installation. Once you’re chrooted, just [...]

Add this to the virtual host configuration if PHPLive says it has no session.save_path:

php_admin_flag safe_mode off
php_admin_flag register_globals off

PHPLive cannot operate with safe_mode enabled.

Remember, if you raise MaxClients for an MPM in Apache, you must raise the ServerLimit directive, which is normally set to 256 on most servers.  The ServerLimit maximum is always obeyed, no matter what MaxClients says. For example, if MaxClients is set to 500 and ServerLimit is 256 (or it is unspecified), then Apache [...]