From chapter two, I learned the basic features of an operating system. For example having a UI like CLI or GUI, ability to execute a program, I/O operations, file-system manipulaton. Furthermore, functions include communications, error detection, resource allocation, protection.
I learned new terms that are used this week, for instance sudo is used for executing commands as a super user. With sudo we can run commands that are considered as special privileges. This is useful because it can minimize mistakes.
After downloading VBox, I created a debian guest. This enables me to have mouse pointer integration, shared folders, shared clipboards, and other functionalities.
I learned that it has a layered approach where operation systems can run on a virtual system. The hypervisor provides an interface that is identical to the host.
I learned that paging and virtual memory are related. Paging is a way of memory to allocate things to CPU as additional memory which is also called virtual memory. Virtual memory can be a part of HDD or SSD. The memory management unit uses virtual memory from the disk to CPU.
Virtual file system is used so that different file systems can be accessed by computer applications in the same manner. The interface provided is consistent to multiple file systems.
Hypervisors are virtual machine managers. Hypervisors create and run virtual machines. There are several types like type 0 which is built with minimum software component. Type 1 is a layer of software installed on a physical server, are basic and runs on a physical machine. Type 2 is also called hosted hypervisors, they have a software layer underneath, they include a physical machine, OS installed on hardware, type 2 hyspervisor software, guest virtual machines.
An emulator is used to emulate which is in the form of either software or hardware. It’s used so that a host/main computer system can behave like another/guest.
Isolation is mainly used for security by keeping programs isolated in their own virtual address space. Virtual address is a physical location of virtual memory. It works by restricting the memory that can be used by a specific program.
Cloud computing delivers applications and other uses as a service across a network. There are three standard models, Infrastructure as a Service (IaaS), Platform as a Service (PaaS), and Software as a Service (SaaS). They enable easier access to applications and resources without internal hardware.