The Helpdesk For I.T. Administrators
The lspci command, which can be found in the pciutils package, is a great tool for finding information on the devices in your PC. the lspci command will allow you to get the model number/chip details for devices such as network interface cards, sound cards, raid cards, etc. To install pciutils on CentOS/RHEL using yum: …
Have you ever replaced a network card on Ubuntu and found that it is now appearing as eth1, instead of eth0? Or simply wanted to swap the numbering of two network interfaces? This guide shows you how to do just that. Ubuntu uses the udev dynamic device management system, and automatically keeps track of what …
For computers to communicate with each other over a network, they need to be able to know how to convert a IP address, into the physical address of the network card (MAC address). If your computer doesn’t have the MAC address for the specific host you are trying to communicate with, your computer will send …
Queue maintenance is an important part of the administration of any SMTP mail server. There may be times where you get a lot of emails attempting to be sent, that either aren’t getting transmitted successfully, or you don’t want them to get transmitted. The “postsuper” command allows you to remove individual emails, or even all …
If you are having issues sending emails with the Postfix SMTP server, the two best places to look to diagnose the issue, are the log files, and the mail queues. Any emails that don’t get sent successfully, or that haven’t been sent yet, will be stored in the queue waiting for transmission/re-transmission. To view the …
Typically if a mail server can’t connect to a remote mail/SMTP server, it will keep the email in a queue and periodically retry sending the email until it is either successful, or fails after a specific time frame which set in the mail server configuration. This tip shows you how to flush the Postfix mail …
Nginx (pronounced Engine-X) is a fast & lightweight HTTP and HTTPS web server (it can also act as a reverse proxy, and perform load balancing). (Note: this is a updated version of a similar how to located here, but this article is using php-cgi package instead of php-fpm, and using only default Ubuntu repository’s). Its …
Below is an example of a PHP-FastCGI init script for use on Ubuntu systems. This startup init script was copied from http://wiki.nginx.org/Ubuntu-php-fastcgi and slightly modified to keep all start up settings in the one script file. Thanks to the original author. It can also be downloaded in full from: http://www.networkinghowtos.com/wp-content/uploads/scripts/php-fastcgi Remember to “chmod +x” this …
This guide will step you through the process of compiling, installing, and setting up the latest version of HAProxy on Ubuntu. Install HAProxy from the repository to get required scripts Install HAProxy using the package management tools first, so we can get a copy of the sample config file, and the start up scripts. Note: …
HAProxy is a very capable load balance, but unless you set up the statistics site, you wont easily be able to view the statistics, and in later versions, take down, and bring up back end servers. This is a great feature that allows you to take one of your back end servers offline without shutting …