Virtual machines first appeared commercially on mainframes in the 1970s.

A microkernel is a kernel containing many components that are optimized to reduce resident memory size.

The "mkdir" command can only create one directory at a time.

A signal propagates at a speed of 300000 km/second. The distance between Jakarta and Kabul is about 6000 km. If the signal frequency is 3GHz, about 600 million cycles will be between Jakarta and Kabul.

In the message-passing model, the communication processes exchange messages to transfer information.

Debugging is finding and fixing errors in a system only in software.

With containerization, we can have multiple OS in one bare metal hardware.

General-purpose operating systems that provide standard functions and Virtual Machine Manager (VMM) functions are known as Type 0 Hypervisor.

Constantly running system-program processes are known as services.

The following command will display the first 10 lines of "log.txt":