Category Archives: Servers

Linux : Export Roundcube webmail contact from SQL to CSV

Here is a procedure how to export the saved address book contacts from Roundcube webmail directly from the MySQL database to a CSV file (please note that Roundcube natively support exporting contacts from the Webmail itself to CSV – this method is only in case you want to pull out old contacts from a database).… Read More »

Linux : How to reset cPanel max defers for a specific account

If one of your hosted user (or account) have accidentally reached the max deferred message that can be sent over an hour (and the issue have been identified and fixed), you can unsuspend the mail delivery by deleting the following file :

For example, if the domain name is ““, the command to execute… Read More »

Windows : Install Ubiquiti Unifi SDN Controller as a service

If you are operating Ubiquiti wireless gear compatible with the Unifi controller, and running it on a Windows machine, you may have noticed that you need to start the application manually every time you restart the computer. Fortunately, there is a way of adding it “as a service”, just like any OS/system services. Follow the… Read More »

Linux : There is no screen to be resumed matching …

Using “screen” on Linux to perform your important work? Way to go, SysAdmin 🙂 Then you might at some point encountered the following behavior – while attempting to resume a session using “screen -r”, the following message occurred : There is a screen on: (25/08/18 08:25:36 PM) (Attached) There is no screen to be… Read More »

Linux : How to get hardware serial number

The easiest way to get hardware serial and related information is using “dmidecode“. The command below should give you exactly what you need :

The command above does not usually work with “clone” computers/servers. Alternatively, you may use the command below, which will output all parts serial number availables :