Linux Primary Stage finishing notes

The development of Unix

1. In1965 , the United States Massachusetts Institute of Technology (MIT), GE, and T Bell Labs jointly developed the Multics project, with the goal of developing interactive time-sharing systems with multi-channel process capabilities. Bell Labs withdrew because of unrealistic expectations.

2. In1969 , the Ken Thompson of Bell Labs developed a UNIX system.

3. In1971 , Ken Thompson colleague Dennis Ritchie invented the C language;

In the 1973 , most of the UNIX system's source code was rewritten in C.

4. Common UNIX Distributions: AIX (IBM), Hp-un (HP), Solaris (SUN)

The History of Linux

1.minix was invented by Andrews.tanenbaum (Tan Ningbong), and in 1987, open source code was given to university teaching and research work.

2.linux was invented by Finnish university student Linustorvalds (Linas Thovas).

Linux kernel version: 2.6.18 (major, Minor, last) www.kernel.org (kernel website)

Linux distributions: RedHat (series), Fedora, CentOS, SUSE, Gentoo, Red Flag, Mandriva, Turbolinux

Ubuntu (series), Debian

Common open Source software: Apache, NGiNX, MySQL, Php, Samba, MongoDB, Python, Ruby, Sphinx

Apache, NgiNX Web Services

MySQL, SQL Server, Oracle relational database SQL

MongoDB, Redis NoSQL database

Samba windows and Linux shared files

Python, Ruby scripting language

Sphinx Chinese Word segmentation, full text Search

Casing Technology: www.netcraft.com (Network statistics)

Key Features of VMware:

You can use more than two operating systems on the same PC without partitioning or rebooting

The native system can communicate with the virtual machine system network

can set and modify the hardware environment of the virtual machine operating system at any time

Two partition tables: MBR partition table (2.1TB) and GPT partition table (9.4ZB)

Partition type:

Primary partition: Up to a maximum of 4

Extended partitions: Up to 1 extended partitions, extended partitions cannot be formatted, cannot be written to data, and can contain only logical partitions. Extended partition plus primary partition up to 4

Logical partition: Numbering starts from 5.

The format is written to the file system.

Windows file System: FAT16, FAT32, NTFS

Linux file systems: EXT2, EXT3, EXT4

File system is divided into blocks and blocks, block can be 1k,2k,4k, default is 4k.

The super block includes the Inode (I node), time and permissions, and the number of inode is limited.

/DEV/HDA1/DEV/SDA1 A: First hard drive 1: First Partition

Hd:ide hard Drive (133mb/s) SD:SCSI HDD (MB/s), SATA hard drive (up to MB/s)

Linux must be partitioned: root partition, swap partition,/boot partition (200M)

Swap partition, swap partition, virtual memory, memory less than 4G, memory twice times, memory greater than 4G, same as memory.

Linux installation steps: partition, format, device file name, mount.

Everything under Linux is a file, including hardware (which requires permanent entry to the configuration file), Linux is strictly case-sensitive, Linux does not differentiate file types with extensions, but permissions, but there are exceptions.

Compressed package: "*.gz", "*.bz2", "*.tar.bz2", "*.tgz"

Binary package: ". RPM"

Web files: "*.html", "*.php"

Script file: "*.sh"

Configuration file: "*.conf"

All Linux storage devices must be mounted before users can use them, including hard drives, USB drives, and discs.

Programs under Windows cannot be installed and run directly on Linux.

Server Considerations :

The remote server does not allow shutdown and can only be restarted.

The service should be turned off when restarting.

Do not run high load commands on server access peaks.

Do not kick yourself out of the server when configuring the firewall remotely.

Specify a reasonable password specification and update it regularly.

Reasonable allocation of permissions.

Back up important data and logs regularly.

Common directories

/bin/ The directory where the system commands are stored, both normal and Superuser can execute. However, commands placed under/bin can also be executed in single-user mode.

/sbin/ Save and system environment settings related commands, only superuser can use these commands for system environment settings, but some commands can allow normal users to view

/usr/bin/ The directory where the system commands are stored, both normal and Superuser can execute. These commands are not related to system boot and cannot be performed in single-user mode

/usr/sbin/ Store root file system unnecessary system administration commands, only superuser can use.

/boot/ System startup directory, save system startup related files, such as kernel files and boot loader files, etc.

/dev/ Device File save location, save all hardware device files

/etc/ configuration file save location, such as user account and password, startup script of service, configuration file of common service, etc.

/home/ The home directory of ordinary users, the user User1 home directory is/home/user1

/lib/ The function library where the system call is saved

/lost+found/ When the system crashes unexpectedly or the machine shuts down unexpectedly, and some file fragments are placed here, when the system starts, the Fsck tool checks here and repairs the corrupted file system, which appears in each partition

/media/ Mount directory, system recommendations are used to mount the media device

/mnt/ Mount directory, the system recommends mounting additional equipment

/misc/ Mount directory, which is recommended for mounting a shared directory for NFS Services

/opt/ Third-party installed software save location

/proc/ Virtual file system, the data of this directory is not saved to the hard disk, but saved to the memory, mainly the kernel of the system, process, external device status and network status.

/sys/ Virtual file system, similar to the/proc directory, is stored in memory, mainly to save kernel-related information

/root/ Super User home Directory

/srv/ Service Data directory, some system services start, you can save the required data in this directory

/tmp/ Temporary directory, the system holds the directory of temporary files, all users in this directory can access and write, it is recommended that this directory do not save important data

/usr/ System software Resources directory, "Unixsoftware Resource", most of the software installed in the system is stored here

/usr/local/ manually installed software save location, it is recommended to install the source code package software installed in this location

/usr/src Source Package save location, manual download source package and kernel source package can be saved here

/var/ Dynamic Data save location. Primarily saves files generated by cache, log, and software operations

/var/log/ System Log Save location

Linux Command Prompt : [[Email protected]~]#

[Current Login user @ The last directory currently in the current hostname]# ~ Home directory #超级用户 $ normal User

Command format: command [options] [parameters] parameter can be file, directory, user, process

The thumbnail option uses a minus sign, and the complete option is two minus

Linux only records 3 time: Last access time, last modified content time, last modified state time

Relative path: Look for the current path. Be sure to first determine the current directory.

Absolute path: Specified from the root, recursive lookup at the first level. In any directory, you can enter the specified location.

This article is from the Linux consolidation Notes blog, so be sure to keep this source http://lt519.blog.51cto.com/10672050/1693258

Linux Primary Stage finishing notes