Ubuntu: Failed to start Nvidia Persistence Daemon

The nvidia-persistenced group/user is created by the install script in the nvidia-utils package (or equivalent if you use one from the AUR). Reinstalling nvidia-utils will recreate the needed nvidia-persistenced group/user. Without reinstalling you can directly run...

ssh: how to fix warning about ECDSA host key

I’m trying to setup password-less SSH on an Ubuntu server with ssh-copy-id myuser@myserver, but I’m getting the error: Warning: the ECDSA host key for ‘myserver’ differs from the key for the IP address ‘192.168.1.123’ What’s...

How to Manage File and Folder Permissions in Linux

For many users of Linux, getting used to file permissions and ownership can be a bit of a challenge. It is commonly assumed, to get into this level of usage, the command line is a must. Although there is always far more power and flexibility to be had, running...

How do I add multiple user to UNIX group?

In Linux, I can create a group: sudo groupadd mygroup and add several users to it: sudo usermod -a -G mygroup userA sudo usermod -a -G mygroup userB sudo usermod -a -G mygroup userC Or, if gpasswd is available (should be on most distributions except e.g. Solaris) you...

SETTING UP JAVA ENVIRONMENT VARIABLE ON EC2

STEPS TO SET JAVA ENVIROMENT VARIABLE ON EC2 IN 4 SIMPLE STEPS. First, check the version of JDK Step 1: Ensure you have right version of JAVA installed or upgrade if necessary (Optional) The latest version of JAVA is 1.8, by default Amazon Linux has JAVA version 1.7...

How do I free up a TCP/IP port?

netstat -tulnap shows me what ports are in use. How do I free up a port in Linux? As the others have said, you’ll have to kill all processes that are listening on that port. The easiest way to do that would be to use the fuser(1) command. For example, to see all...