Linux

Recent work has often been used to some useless Linux commands, recorded, often updated.2018.4.24View image size: Identify filename to view the JPG format, file filename to view the PNG format, you need to install ImageMagick first.Number of files

Virtual local Area network (VLAN) is a set of logical devices and users, these devices and users are not limited by the physical location, can be based on functions, departments and applications and other factors to organize them, communication with

What is a file systemA file system is a way to store and organize your computer's files and data, making it easy to access and findFile systems typically use storage devices such as hard disks and discs, and maintain the physical location of files

What is a home directory?Is the directory of user files for all users other than root. Your own files are put here.such as test users, their personal data and desktop and other files are placed under the/home/test/directory.LESS/ETC/PASSWD files for

7.1 Three ways to install packagesRPM Tool: Similar to the EXE file under Windows.Yum tool: Supports automatic installation of dependent packages. Equivalent to the App Store.SOURCE package: All kinds of programming language files can be seen, need

Nginx is a high-performance reverse proxy server, now generally as the first layer of our website or other Web services agent, the user in the browser request first pass is the Nginx service.If the Nginx service does not start or end unexpectedly,

Crond Process:Crond is a daemon used to periodically perform certain tasks under Linux, installing the operating system installs the service tool by default, and the Crond process is started automatically, and the Crond process periodically

Disk ManagementEquipmentDevice filesDevice typeBlock: Random access as a "block", such as a hard diskCharacter device (char): In "character" units, sequential access to keyboardDevice numberMain device number (major): Identifies the device

commands for viewing the contents of a file under LinuxCommands to view the contents of a file:Cat starts displaying content from the first line and outputs all contentThe TAC displays the contents in reverse from the last line and outputs all the

Keys To work Space key Turn down one page [Page down] Turn down one page [Page up] Turn up one page [Ctrl + U] Turn up one page [Ctrl + D] Turn down

APP| || GNU C Library| | (upper layer is user space, lower layer is kernel space)System Call Interface|Visual File System (abbreviated VFS, virtual file systems)|Individual file system (various types of filesystems, such as NTFS, FAT, EXT2, EXT3,

Three types of HDD management:Add a disk three steps:1. Add disk 1.1 basic diskThe virtual machine manually adds a hard drive of 1 blocks of 4G size and requires a reboot for the experiment:Fdisk-l List all hard drive names and locations on the

Show All Processes PS AShow All programs under the same terminal ps–aShow related processes for active users ps–uList the more complete information ps–xQuerying system All process data PS auxViewing processes that are not related to terminal PS

服务器中的集群与网络中的集群虽然都是为了提供冗余的服务能力，但是在实现上有一定的差异，主要原因为网络冗余只需要实现流量有冗余路径，当主的链路故障后，流量可以通过备的链路通行即可。对于有状态的如TCP协议，某些设备如防火墙需要对其进行状态检测，那么只需要在主备设备之间开启会话同步功能即可。但是对于服务器而言较为复杂，主要原因是因为服务器作为流量的终结点，是需要直接对外提供服务的，其上存储的数据则需要被服务访问，不再是流量穿越就可以。本人一起从事网络相关的工作，在第一次接触服务器集群时，对其实现原理

Recently are learning Python, back to think about it or review Linux Rights Management, summed up a bit. After all, before learning Java, for the basis of the object-oriented are more familiar with, so it will not be too difficult to learn, and took

One　　　　　　　　　　/----root directory (unique)/---bin: (binary shorthand), there are some system-level command files, easily do not operate files under this folder.--dev: (abbreviated device), you can mount some other devices.--home: The user's home

The reason is that the environment variable (cross-compilation path) may be added under a normal user, so the file created under root user cannot find ARM-LINUX-GCC when it is compiled with ARM-LINUX-GCC.Workaround: Find a terminal: sudo-sSOURCE

Linux system Operations NotesLinux file editing commandsFirst we use the command VI filename to open a file, this time to enter the command modeNext we press I, then the keyboard casually enter the content.Then press ESC to re-enter the command mode.

Generate system Resource Usage statistics, this program also needs to be installed, the system does not own the defaultDstat N MN Refresh IntervalM Refresh TimesThe default will always brush downThis command is very powerful and needs to be studied

Displays the memory-mapped table for the specified processThis command is for information only and I don't think I will use this command for a lifetime.Here I just want to say one thing, is that the idea of Linux is all files, then the corresponding