Review UNIX LINUX BSD architecture

1. Computer hierarchy

650) this.width=650; "title=" clipboard "style=" Border-top:0px;border-right:0px;background-image:none; border-bottom:0px;padding-top:0px;padding-left:0px;margin:0px;border-left:0px;padding-right:0px; "border=" 0 "alt = "Clipboard" src= "Http://img1.51cto.com/attachment/201408/11/8976580_1407764002Aeis.png" height= "227"/>

2. At the heart of every Unix, Linux, and BSD system are the kernel. Kernel is the core of all UNIX, LINUX,BSD systems

Tapping the keyboard-the hardware transfers the content to the kernel-kernel-output to the display-if executable-invokes the processor, memory, and other resources to perform the task.

650) this.width=650; "title=" clipboard[1] "style=" border-top:0px;border-right:0px;background-image:none; border-bottom:0px;padding-top:0px;padding-left:0px;margin:0px;border-left:0px;padding-right:0px; "border=" 0 "alt = "Clipboard[1]" src= "http://img1.51cto.com/attachment/201408/11/8976580_1407764003BNRN.png" height= "215"/>

3. A wide variety of versions

650) this.width=650; "title=" clipboard[2] "style=" border-top:0px;border-right:0px;background-image:none; border-bottom:0px;padding-top:0px;padding-left:0px;margin:0px;border-left:0px;padding-right:0px; "border=" 0 "alt = "Clipboard[2]" src= "http://img1.51cto.com/attachment/201408/11/8976580_14077640043zp4.png" height= "/>"

650) this.width=650; "title=" clipboard[3] "style=" border-top:0px;border-right:0px;background-image:none; border-bottom:0px;padding-top:0px;padding-left:0px;margin:0px;border-left:0px;padding-right:0px; "border=" 0 "alt = "Clipboard[3]" src= "http://img1.51cto.com/attachment/201408/11/8976580_1407764004CnVF.png" height= "/>"

BSD 4.3 mixes proprietary t/t UNIX code, and continues to require license from/to, the source license was very expensive at the time, several other organizations on separate network code

Interested, this part is completely independent of AT/t (at/T recovery UNIX Code)

650) this.width=650; "title=" clipboard[4] "style=" border-top:0px;border-right:0px;background-image:none; border-bottom:0px;padding-top:0px;padding-left:0px;margin:0px;border-left:0px;padding-right:0px; "border=" 0 "alt = "Clipboard[4]" src= "Http://img1.51cto.com/attachment/201408/11/8976580_1407764005Etnl.png" height= "143"/>

4. The Agreed directory structure

General rules configuration files is located in The/etc directory and system logs is stored in/var/log.

650) this.width=650; "title=" clipboard[5] "style=" border-top:0px;border-right:0px;background-image:none; border-bottom:0px;padding-top:0px;padding-left:0px;margin:0px;border-left:0px;padding-right:0px; "border=" 0 "alt = "Clipboard[5]" src= "http://img1.51cto.com/attachment/201408/11/8976580_1407764006Elfq.png" height= "244"/>

4. Important File Directories

650) this.width=650; "title=" clipboard[6] "style=" border-top:0px;border-right:0px;background-image:none; border-bottom:0px;padding-top:0px;padding-left:0px;margin:0px;border-left:0px;padding-right:0px; "border=" 0 "alt = "Clipboard[6]" src= "http://img1.51cto.com/attachment/201408/11/8976580_1407764008ZJL9.png" height= "244"/>

4. Common File System architecture

650) this.width=650; "title=" clipboard[7] "style=" border-top:0px;border-right:0px;background-image:none; border-bottom:0px;padding-top:0px;padding-left:0px;margin:0px;border-left:0px;padding-right:0px; "border=" 0 "alt = "Clipboard[7]" src= "Http://img1.51cto.com/attachment/201408/11/8976580_1407764009mKpN.png" height= "Bayi"/>

EXT 2-4 Linux (currently used in version four, there are many updates, mentioned separately in the File System Architecture section)

A file system that JFS IBM is doing on AIX

Hfs+ Apple's file system on unix-based MAC OS X, which is not supported by other operating systems, but can be mounted as a readable Linux file system

VxFS veritas-now Simon · Primarily in HP-UX

The file structure used by ZFS on Sun Solaris also has limited support for Linux and BSD systems

4. Devices Equipment

Like/dev/mouse Dev/cdrom and the like.

650) this.width=650; "title=" clipboard[8] "style=" border-top:0px;border-right:0px;background-image:none; border-bottom:0px;padding-top:0px;padding-left:0px;margin:0px;border-left:0px;padding-right:0px; "border=" 0 "alt = "Clipboard[8]" src= "Http://img1.51cto.com/attachment/201408/11/8976580_1407764010JQlY.png" height= "198"/>

More special several/dev under

650) this.width=650; "title=" clipboard[9] "style=" border-top:0px;border-right:0px;background-image:none; border-bottom:0px;padding-top:0px;padding-left:0px;margin:0px;border-left:0px;padding-right:0px; "border=" 0 "alt = "Clipboard[9]" src= "http://img1.51cto.com/attachment/201408/11/8976580_14077640108i0Y.png" height= "/>"

4. The meaning of the Shell user login interface

$

Normal user shell (may also is% or > on some systems)

#

Root User Shell

[Email Protected]:/var/log $

650) this.width=650; "title=" clipboard[10] "style=" border-top:0px;border-right:0px;background-image:none; border-bottom:0px;padding-top:0px;padding-left:0px;margin:0px;border-left:0px;padding-right:0px; "border=" 0 "alt = "clipboard[10]" src= "http://img1.51cto.com/attachment/201408/11/8976580_1407764011aBhg.png" height= "/>"

The type of shell, Redhat by default is bash, when we write the shell, the first line is to declare what kind of shell

650) this.width=650; "title=" clipboard[11] "style=" border-top:0px;border-right:0px;background-image:none; border-bottom:0px;padding-top:0px;padding-left:0px;border-left:0px;padding-right:0px, "border=" 0 "alt=" clipboard [One] "src=" http://img1.51cto.com/attachment/201408/11/8976580_1407764011ILhO.png "height="/>