Operation and maintenance of the pre-summary
Operation and maintenance of basic job responsibilities : Web site data can not be lost, site 24- hour operation, enhance the user experience, ask the server stability than home machine, simple, easy to use, efficient
It works main battlefield
Features: build server used for the site, compared to other desktops, laptops, and more plus stable set , and more plus can rely on .
Description: server, also known as server (Taiwan), is to provide computing services equipment. Because the server need to respond to service your request and processed, so in general the server should have the ability to take service and security services. Server package configuration similar includes a processor, hard drive, memory, a system bus, and general computer architecture, but due to the need to provide highly reliable service business, and therefore the processing can force , stability constant resistance , can be by nature , security whole of , can be expanded exhibition of , manageability demanding
1U server ( the U- represented thickness server) 1U = 1.75 inch = 4.445CM = 4.45
Server according to shape classification: rack servers (like a drawer), server blade , tower server
Rack-mounted servers
Blade piece server
Tower Servers
Computer and server main components
Internet companies server brand
- DELL (most companies, commonly used)
- HP - IBM (Baidu in use) - wave - Lenovo - Space Unisign
IBM brand 1U 3550 / m3 3550 / m5 2U 3650 4U 3850 8U 3950 only for understanding, good quality, but expensive, Internet companies less common IOE (IBM oracle emc)
1.1.3 HP brand DL380G7 / G8 (2u)
Size of the disk 1byte = 8bit 1K = 1024byte 1M = 1024K 1G = 1024M 1T = 1024G 1PB = 1024T bytes (byte): 8 binary bits of a byte (B) are sold in the market by 1000 calculates hard disk, known 500G hard drive = 500 * 1000B * 1000KB * 1000MB
What is the difference between buffer and cache
Write data to memory, this memory space is called a data buffer ( Buffer),
Write buffer.
Reading data from the memory, the data stored in this memory region is called the cache ( Cache), read cache region.
Since 99% of sites are mainly to read, write, supplemented by literacy ratio of at least 10: 1, it is concurrent writes is generally not a problem.
Unix Top 5 Benefits Features
技术成熟，可靠性高 极强的可伸缩性 Unix支持的CPU处理器体系架构非常多，包括Intel／AMD及HPPA，MIPS，PowerPC，UltraSPARC，ALPHA等RISC芯片，以及SMP，MPP等技术
1，linux的发展历程简介
1）1984年，Andrew S.Tanenbaum开发了用于教学的Unix系统，命名为MINIX。 2）1989年，Andrew S.Tanendaum将MINIX系统运行于x86的PC计算机平台
3）1990年，芬兰赫尔辛基大学学生Linus Torvalds首次接触MINIX系统
4）1991年，Linux Torvalds开始在MINIX上编写各种驱动程序等操作系统内核组件。
5）1991年底，Linus Torvalds公开了Linux内核源代码0.02版，注意，这里公开的Linux内核源 码并不是我们现在使用的Linux系统的全部，而仅仅是Linux内核kernel部分的代码。
6）1993年，Linux1.0版发行，Linux转向GPL版权协议 7）1994年，Linux的第一个商业发行版Slackware问世。
8）1996年，美国国家标准技术局的计算机系统实验室确认Linux版本1.2.13（由Open LInux公 司打包）符合POSIX标准
9）1999年，Linux的简体中文发行版问世
10）2000年后，Linux系统日趋成熟，涌现大量基于Linux服务器平台的应用，并广泛应用于基 于ARM技术的嵌入式系统中。