21 articles Linux

Linux Articles pertaining to Operating System’s:
Redhat Enterprise (Rhel)
Centos
Ubuntu
Debian

Apache Client Connection Parameters

Short explanation of the parameters: This will help you understand what to change in your Apache config file when trying to tune Apache to be memory efficient and provide enough connections for your site viewers. ServerLimit Declares the maximum number of running apache processes. If you change this value you have to restart the daemon.…

Linux set facl command

About setfacl The setfacl command sets file access control lists. Permissions Required To Modify ACLs The file owner and processes capable of CAP_FOWNER are granted the right to modify ACLs of a file. This is analogous to the permissions required for accessing the file mode. On current Linux systems, root is the only user with…

Using Yast Text Based Control Center.

First off here is the official Documentation Yast Control Panel makes linux administration extremely easy. You can search for a package to install such as apache, click a button and it is installed. Want to setup up your firewall to open port 80? Click a few options in the menu. Want to run a update…

Rackspace phpmyadmin install method ran with Apache

 Rackspace phpmyadmin install method ran with Apache Centos Install Instructions: First lets see if it’s installed: Centos/Redhat: yum list installed |grep -i phpmyadmin   Check to see if phpmyadmin is in the current Repo’s you have: yum list |grep -i phpmyadmin Note:CENTOS/REDHAT ONLY!  If it is not in the Repo you will have to install…

Postfix unable to recieve email from some senders.

 Postfix unable to recieve email from some senders. You may run into a problem with Postfix when you are not getting a message from a few senders, but receiving messages from everyone else.  It is likely that you have SPF checker enabled in Postfix’s main.cf config file and the senders have malformed, or incomplete SPF…

How Do I Whitelist Hosts/IP Addresses In Postfix?

How Do I Whitelist Hosts/IP Addresses In Postfix? If you are not recieving emails from a sender to Postfix, this could be due to issues with the senders SPF record being incomplete, or malformed. If you really need to get emails from the sender one way would be to whitelist the ip or host address…

Ansible copy files to multiple servers.

There are many ways to copy a file over to many servers, but I think using Ansible with a adhoc command is a simple way to get it done with my method.  For official documentation see here: http://docs.ansible.com/ansible/intro_adhoc.html#file-transfer Step 1. Install Ansible I like to install ansible in a virtualenv with pip. Create a VirtualEnv…

Ansible Reload Apache on multiple servers

Sometimes you’d like to reload Apache after a config change on several servers. ansible adhoc commands makes this pretty simple. Step 1. Install Ansible I like to install ansible in a virtualenv with pip. Create a VirtualEnv Install pre-reqs Ubuntu: apt-get update && apt-get install python-apt python-pip build-essential python-dev git python-virtualenv -y RHEL/CentOS: yum install…