The Helpdesk For I.T. Administrators
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 …
If you have your display’s DPI (Dots Per square Inch) setting set to something greater than 96 DPI (which is the default) in Windows XP, you may find that some applications don’t display text/form elements correct, and may get cut off the screen. Changing the DPI back to 96, and rebooting, should fix this issue …
If you don’t have a RAID add-on card (or have RAID capabilities on your motherboard), but you would still like to have some level of redundancy due to hard disk failure, you can set up a software RAID1 array. RAID1, otherwise known as mirroring, simply duplicates all writes to one drive, to another. If one …
Changing the port number that your SSH server listens on is a simple way to prevent random brute force login attacks against your server. While people can still perform attacks against SSH running on a different port number, most automated tools will default to port 22, and not actually do a full port scan. Any …