How to duplicate a Windows server that is attached to the Windows Domain

When a Windows server is attached to a Domain only one instance of it can run at a time. To be able to duplicate the server and start a second instance of it Create an image of the server Remote into the server Make sure there is a local administrator account that you can log […]

Unable to insert the virtual optical disk in an Ubuntu virtual machine

When you try to install a new version of the VirtualBox Guest Addition on an Ubuntu virtual machine you may get the error message Unable to insert the virtual optical disk C:\Program Files\Oracle\VirtualBox\VBoxGuestAdditions.iso into the machine Ubuntu 64. Could not mount the media/drive ‘C:\Program Files\Oracle\VirtualBox\VBoxGuestAdditions.iso’ (VERR_PDM_MEDIA_LOCKED). Result Code: E_FAIL (0x80004005) Component: ConsoleWrap Interface: IConsole {872da645-4a9b-1727-bee2-5585105b9eed} […]

Raw-mode is unavailable courtesy of Hyper-V error in VirtualBox

For VirtualBox to be able to start virtual machines, Hyper-V has to be turned off in Windows 10. If you get the error message when you try to launch a virtual machine in VirtualBox Raw-mode is unavailable courtesy of Hyper-V Check the Hyper-V setting Open a command prompt as an administrator, Execute the command: bcdedit […]

Windows application installation error codes

To enable logging of .msi packages open a command prompt as an administrator and execute MY_APPLICATION.msi /l*vx install.log Error Code Explanation 2 ? 1603 Error message from the operating system dll can not register msi installation failed required version of the .NET framework missing 1605 Nothing to uninstall ? 1618 ? 1619 The source directory does […]

Set up a user to connect to a Linux server with a private-public key pair

To secure a Linux server, disable password authentication on it. This way only those users can connect to it, who have access to an authorized private key. To enable users to connect to a Linux server with a private-public key pair Generate an RSA key pair In a Bash terminal on your workstation execute ssh-keygen Follow […]

Set up an application to auto-start on macOS

To set up an application to automatically start when the Macintosh computer starts Open Settings Select Users & Groups On the Login Items tab click the lock to enable changes Enter your credentials to unlock the function Click the + sign to add an application to the list Select the application and click the Add button

The user account does not have permission to run this task

When a Scheduled task is created by another user (or SYSTEM) most of the time only that user can manually trigger the task execution. When you try to execute the scheduled task from the user interface you can get the error message: The user account does not have permission to run this task This error […]

Error loading table definition of a PostgreSQL table

When a PostgreSQL table name contains uppercase letters there is no known way to get the table definition SQL script. When we right-click a table name in SQLPro for Postgres the has an uppercase letter and select Script as, CREATE to, New query window we get the error message /* * Error loading table definition. * ERROR: […]

Copy files between Linux machines

The rsync command allows you to copy files using SSH connection, between your workstation and another Linux machine. You have to be logged into one of the machines, this command cannot copy files between two remote machines. To copy a file from your local machine to a remote server rsync -avz -e “ssh -i SSH_KEY_FILE -o […]

Using tmux terminal multiplexer

The tmux terminal multiplexer allows us to open multiple terminal windows in the same SSH session and continue the command execution even when we log out of the SSH session. This way we can execute long-running copy commands overnight without keeping the SSH session open. Install tmux On CentOS family Linux yum install tmux To start tmux […]