1, the installation
a, directly to the operating system installed on a hardware device (too much trouble, do not recommend) (dual-system mode) b, using VMM management platform to install (virtual machine mode) "VMM management platform: VMware workstation, Virtualbox"
Choose language - choose Keyboard - selected time zone - to write the host name - Define the root password (superuser) - dividing up the disk space (partition must be divided into three: / boot reboot)
Detailed steps to install Mac link (on Mac VMWare virtual machine to install Linux-Ubuntu used) https://www.cnblogs.com/taostaryu/p/9404615.html
Windows ( installation of Linux-Ubuntu with VMWare virtual machine on Windows ) detailed steps link https://blog.csdn.net/meiqi0538/article/details/88406909
Ubuntu image file Download https://launchpad.net/ubuntu/+cdmirrors?_ga=2.214379024.606055489.1564658320-701372154.1564479660
CentOS image file Download https://www.jianshu.com/p/a63f47e096e8
c, take a snapshot, if an error occurs, you can restore a snapshot! ! !
2, computer performance:
Scale-out cluster "strength in numbers": cluster load balancing, high availability clustering, high-performance cluster "application layer" - hadoop cluster
Longitudinal extension (in other machine) application migration
Start system
--power supply
--BIOS chip
1, POST, check the hardware device is working properly.
2, start the system, select the system starts "1, reading order problem to be addressed location where the system: hard disk, network (PXE), U disk, CD / DVD ... 2, you need to load the system files on your hard disk into memory, let the CPU reads and runs .MBR partition (BootLoader "LILO, grub"), to find and boot the system load ")
Kernel is loaded, however, and can not run common applications
--init
At this point, you need to run your first application - init (init: The operating system is divided into seven "0--6" levels, each level will run a corresponding application "to specify the default start level")
- read the default level 3 (command line) "0: off 1: single-user mode (safe mode) 3: Command Line 5: GUI 6: Restart" - chkconfig / rc * d (each of the required level. the process started)
- Read rc.local, the system starts to read the final document, you would require the administrator can run the boot command, add here
chkconfig role:
Designated service boot at which level to start or shut down; -h / -help view help; list; level 12345 Name <on | off>;
update-rc.d certain control program in the boot Ubuntu; -f (force mandatory)
The basic format of Linux command:
Command [options] [parameters]
[]: Brackets denote the optional; specify a particular function to achieve command;
<>: Command object represents; without added <> stands can not be omitted;
Long integer option
* Short integer short int options can be combined, and long integer can not be combined
Extended: command subcommand [options] Parameters
The basic use of commonly used Linux commands
echo $ PATH // environment variable (variable: some are named in memory only)
If the command is not in the PATH, how to solve?
1, run by the absolute path of the command (absolute path is executing the command itself; and some commands, the system default alias "you can add your own" - alias; which command // Find command absolute path; \ ls // use of anti diagonal run directly)
2, adds this path to the lower path PATH ( PATH = $ PATH: / XXX / XXX)
ls // display file information
-l // For more information see the file (property), abbreviated as ll;
-i // inode (attribute);
-h // human human readable;
-F // display tag of a file (used to distinguish the file type);
-r // reverse display file contents;
-a // show all files (including hidden files)
pwd // Display the current path; $ PWD have a default this environment variable;
cd // switch to the target directory;
- the current user's home directory (/ root / home);
The current directory (. Files beginning with a hidden file);
.. the parent directory of the current directory;
- $OLDPWD存放上一次经过的目录；
touch //修改时间戳
Stat atime 访问时间 mtime 修改文件内容的时间 ctime修改文件属性
touch a.txt
[[CC]YY]MMDDhhmm[.ss]
20 19 0 8 01 16 36 . 22
-a 修改访问时间；
-m 修改修改时间；
-t 指定修改成什么时间；
-c 修改文件Mtime，如果文件不存在，不创建该文件
mkdir //创建文件夹；
-p 递归创建多级子目录；
-v 详细显示创建过程；
tree 以树状形式显示目录及文件结构（-L NUM 查看多少级子目录；-d 只显示目录文件）
rm //删除；
-f force强制；
-i 询问是否删除文件，默认命令（alias rm = ‘rm -i’）；
\rm abc ；/bin/rm abc；
-r 删除目录文件
clear //清屏 = ctrl + l