Small vegetable Seeds Linux Week study note "01"

The Linux Basic Law:

Android:

LINUX+JVM (Java Virtual machine on embedded platform) +java program JVM degrades performance and requires two translations

Ios:

Freebsd+object-c (Swift) writes a program that runs directly on the hardware, so it's faster than a virtual machine

1. All documents (including hardware) (everything is a file)

2. Consisting of a number of small programs of a single purpose

3. Combine small programs to complete complex tasks

4. Avoid capturing user interfaces as much as possible, in order to facilitate scripting for automated execution

5. Save program configuration data using a text file: System and service configuration work with a text editor

Introduction to Linux system hierarchy

Run the program: use the kernel to schedule its application to hardware to execute its instructions

User interface: A unique application that provides a mechanism for users to launch other applications

CLI (Command line interface)

Command prompt: The user enters the command to execute

Shell: Shell in broad sense is the user interface, in the narrow sense is Linux command line sh,csh (ELL), Ksh,bash,zsh,tcsh,linux release default use bash

GUI (Graphic user interface): Launch application with click-through Gnome (c development) KDE (R + + development) XFCE (lightweight desktop environment)

See what shell command to use: Echo $SHELL

Linux system hierarchy, hardware--kernel--Runtime--Application

Terminal types for Linux

Servers generally do not need to log on, even the display does not need interactive operation

Virtual Terminal: Now more than the PC (performance is/dev/tty#)

Pseudo Terminal: Remote connected terminal is pseudo terminal, (performance is/dev/pts/#) (Ctrl+alt+f[1-6])

Physical Terminal: (using the VGA interface, console console) (performance as/dev/console)

Serial Terminal: (no graphics card, using serial port output, such as POS) (Performance of/dev/ttys#)

Graphics Terminal: Ctrl+alt +f7 (X window has not been started before, can be switched to GUI by the following command StartX & StartX--: 2 $ has been launched after X window can be activated by the following shortcut key to start Ctrl+alt+f7 ↑)

Order Summary and Landing

Ls,ifconfig,startx,echo,tty

There is a difference between the different types of terminal types and the corresponding representation files.

User: Identify Yourself

Password: Authentication identify user

Knowledge Framework:

Basic Linux Knowledge

System Management

Shell script Programming

Linux Service Management

OpenSSL, Web,ftp,samba. Nfs,dhcp,dns

MySQL Database system

Linux Cluster

Lb:lvs,nginx,haproxy

Ha:heartbeat,corosync,rhcs,keepalived

distributed applications;

MogileFS

MongoDB (NoSQL)

Hdfs

Mapreduce

cache system; varnish

Virtualization; xen,kvm,openstack

monitoring and automation;

Zabbix,puppet,cobbler,ansible

Python

Computer Basics-Bus Type

Bus:

Address bus: Used for addressing

Control bus: Controller sends control signal

Data bus: Transmission

Hardware Equipment 5 core components: Operators, controllers, memory, I/O (input, output devices) Each IO device has a controller

North Bridge: Also known as the Main Bridge (Hostbridge) is responsible for the connection with the CPU and control the memory, AGP, PCI data inside the North bridges transmission

South Bridge: (Southbridge) South Bridge chip is mainly responsible for external equipment data processing and transmission.

The main function of North Bridge chip is data transmission and signal control. It exchanges signals with the CPU through the front-end bus, on the other hand, and the memory, AGP, South Bridge

Interrupt: Interrupt

Hard interrupt: (Hi) hardware-generated interrupts

Soft interrupt: (Si) from user mode to kernel mode is implemented by soft interrupt

File systems: Sub-regions, marking, more blocks, more indexes, but fewer blocks means more wasted space

Poll mechanism: Low efficiency interrupt mechanism

Notification mechanism: Signal arrival notification, CPU interrupt notification related device execution

This article is from the "http://2226547009.blog.51cto.com/13402918/1978805 Linux" blog, so be sure to keep this source.

Small vegetable Seeds Linux Week study note "01"