CISCO Chapter 3 Flashcards
Systems administrators do far more than manage servers; they are often called upon to assist users with _________ , _________ , and _________.
- configuration issues
- recommend new software
- update documentation among other tasks
Most Linux distributions allow users to download a “_________” installation package that can be loaded onto a USB key.
desktop
This is one of the first things aspiring system administrators should do
download a major distribution and load it onto an old PC
The Linux desktop should be familiar to anyone who has used a PC or Macintosh with icons to select different programs and a “settings” application to configure things like _________, _________, and _________
- user accounts
- WiFi networks
- input devices
After familiarizing oneself with the _________, or desktop, the next step is learning how to perform tasks from the command line.
Linux Graphical User Interface (GUI)
It is a simple text input system for entering anything from single-word commands to complicated scripts.Most operating systems have a _________ that provides a direct way of accessing and controlling the computer.
command line interface (CLI)
On systems that boot to a GUI, there are two common ways of accessing the command line:
- GUI-based terminal
- virtual terminal
is a program within the GUI environment that emulates a terminal window. It can be accessed through the menu system or search bar.
GUI terminal
Accessing the GUI terminal through the menu system.
click:
- Applications (menu bar)
- System tools
- Terminal
A _________ can be run at the same time as a GUI but requires the user to log in via the terminal before they can execute commands (as they would before accessing the GUI interface).
virtual terminal
Each Linux desktop distribution is slightly different, but the application terminal or _________ will open a terminal window from the GUI.
x-term
While there are subtle differences between the terms _________ and terminal window sessions, they are all the same from an administrators standpoint and require the same knowledge of commands to use
console
Ordinary _________ are starting programs, parsing scripts, and editing text files used for system or application configuration.
command line tasks
The _________ of the operating system is like an air traffic controller at an airport, and the applications are the airplanes under its control.
kernel
The _________ decides which program gets which blocks of memory, it starts and kills applications, and it handles displaying text or graphics on a monitor.
kernel
_________ make requests to the kernel and in return receive resources, such as memory, CPU, and disk space.
Applications
Applications make requests to the kernel and in return receive resources, such as _________, _________, and _________
- memory
- CPU
- disk space
If two applications request the same resource, the kernel decides which one gets it, and in some cases, _________ to save the rest of the system and prevent a crash.
kills off another application
The _________ also abstracts some complicated details away from the application. For example, the application doesn’t know if a block of disk storage is on a solid-state drive, a spinning metal hard disk, or even a network file share.
kernel
Applications need only follow the kernel’s _________ and therefore don’t have to worry about the implementation details.
Application Programming Interface (API)
Each_________ behaves as if it has a large block of memory on the system; the _________ maintains this illusion by remapping smaller blocks of memory, sharing blocks of memory with other applications, or even swapping out untouched blocks to disk
- application
* kernel
The kernel also handles the switching of applications, a process known as _________.
multitasking
A _________ has a small number of central processing units (CPUs) and a finite amount of memory.
computer system
The _________ takes care of unloading one task and loading a new one if there is more demand than resources available.
kernel
When one task has run for a specified amount of time, the _________ pauses it so that another may run.
CPU
a network service that talks to a remote computer
user-facing application
The kernel doesn’t differentiate between a _________ , a network service that talks to a remote computer, or an _________ .
- user-facing application
- internal task
A _________ is just one task that is loaded and tracked by the kernel.
process
note:
An application may even need multiple processes to function, so the kernel takes care of running the processes, starting and stopping them as requested, and handing out system resources.
The _________ can run a wide variety of software across many hardware platforms.
Linux kernel
A computer can act as a _________, which means it primarily handles data on others’ behalf
server
A computer can act as a _________, which means a user interacts with it directly.
desktop
The machine can run software or be used as a development machine in the process of creating _________.
software
A _________ can even adopt multiple roles as Linux makes no distinction; it’s merely a matter of configuring which applications run
machine
One resulting advantage is that _________can simulate almost all aspects of a production environment, from development to testing, to verification on scaled-down hardware, which saves costs and time.
Linux
A _________ could run the same server applications on a desktop or inexpensive virtual server that are run by large internet service providers
Linux administrator
Of course, a _________ would not be able to handle the same volume as a major provider would, but almost any configuration can be simulated without needing powerful hardware or server licensing.
desktop
Linux software generally falls into one of three categories:
- Server Applications
- Desktop Applications
- Tools
may not talk to other computers but only sit there and crunch data.
Server Applications
Software that has no direct interaction with the monitor and keyboard of the machine it runs on.
Server Applications
The Server Applications’ purpose is to serve information to other computers, called _________.
clients
are web browsers, text editors, music players, or other applications with which users interact directly.
Desktop Applications
A loose category of software that exists to make it easier to manage computer systems.
tools
it can help configure displays, provide a Linux shell that users type commands into, or even more sophisticated tools, called compilers, that convert source code to application programs that the computer can execute.
tools
that convert source code to application programs that the computer can execute.
compilers
is where the users type commands into
Linux shell
The _________ of applications varies depending on the distribution. Often application vendors choose a subset of distributions to support.
availability
Some applications, however, like _________ and _________ are widely supported and available for all major distributions.
- Firefox
- LibreOffice
_________ is an important skill to be learned by the aspiring Linux administrator. Determining requirements for performance, stability, and cost are just some of the considerations needed for a comprehensive analysis.
Evaluating application software
excels at running server applications because of its reliability and efficiency. The ability to optimize server operating systems with just needed components allows administrators to do more with less, a feature loved by startups and large enterprises alike.
Linux
A _________ hosts content for web pages, which are viewed by a web browser using the HyperText Transfer Protocol (HTTP) or its encrypted flavor, HTTPS.
web server
What is HTTP/HTTPS
HyperText Transfer Protocol / HyperText Transfer Protocol Secure
The web page itself can either be _________ or _________ .
- static
- dynamic
Users can develop content through their browser in the ________ application, and the software turns it into a fully functional dynamic website.
WordPress
is the dominant web server in use today.
Apache
Apache was originally a standalone project, but the group has since formed the ________ and maintains over a hundred open source software projects
Apache Software Foundation
is the daemon, or server application program, that “serves” web page requests.
Apache HTTPD
Another web server is ________, which is based out of Russia.
NGINX
It focuses on performance by making use of more modern UNIX kernels and only does a subset of what Apache can do.
NGINX
Over ________ of websites are powered by either NGINX or Apache.
65%
The ________ project was launched in 2010 by Frank Karlitschek to provide software to store, sync and share data from private cloud servers.
ownCloud
Who launched ownCloud project?
Frank Karlitschek
The ________ project was forked from ownCloud in 2016 by Karlitschek and has been growing steadily since then.
Nextcloud
2 private cloud servers:
- ownCloud
- Nextcloud
________ applications form the backbone of most online services.
Database server
________ applications pull data from and write data to these applications.
Dynamic web
a web program for tracking online students might consist of a front-end server that presents a web form. When data is entered into the form, it is written to a database application such as ________.
MariaDB
A ________ stores information and also allows for easy retrieval and querying
database
Example of popular databases:
- Firebird
- PostgreSQL
You might enter raw sales figures into the database and then use a language called ________ to aggregate sales by product and date to produce a report.
Structured Query Language (SQL)
When discussing email servers, it is always helpful to look at the 3 different tasks required to get email between people:
- Mail Transfer Agent (MTA)
- Mail Delivery Agent (MDA)
- POP/IMAP Server
software that is used to transfer electronic messages to other systems
Mail Transfer Agent (MTA)
The most well known Mail Transfer Agent MTA
Sendmail
is another popular one and aims to be simpler and more secure than Sendmail.
Postfix
Types of Mail Transfer Agent
- Sendmail
- Postfix
it takes care of storing the email in the user’s mailbox. Usually invoked from the final MTA in the chain.
Mail Delivery Agent (MDA)
Mail Delivery Agent (MDA) is also called?
Local Delivery Agent
are two communication protocols that let an email client running on your computer talk to a remote server to pick up the email.
POP/IMAP Server
POP means?
Post Office Protocol
IMAP means?
Internet Message Access Protocol
is a popular POP/IMAP server owing to its ease of use and low maintenance.
Dovecot