Linux server how to and tips

The Linux sevrer, its system, services, modules and packages

Server connection :

IP connection notification.
Server SSH login history with a list of the ip connections.

Server status :

How much memory we have.
Find block size.
Get the memory status.
Get the processor status.
VPS high memory usage.
More info about memory usage.
Get the disk space.
How to find the hour in your server.

Services and modules :

List of the services running on the server.
Delete a module.
List the installed packages in Debian.

System :

What Linux operating system we have.
Command 32 bit or a 64 bit operating system.