Linux Operations First Lesson

The first chapter:

type of server:

1.) Rack-mounted Server (drawer type)

2.) Blade type Server

3.) Tower Server

Server Size: thickness (height 1u=4.45.cm)

Server's Manufacturer:

Dell (Dell) (domestic primary server)

Association

Hp

IBM (it's too expensive for a good company)

Wave

Dell Server For example

Time	1U	2U
2010 ago	1850,1950	2850,2950
2010-2013	r410,r610	R710 (Discontinued)
2014-2016	r420/r430/r620/r630	r720/r730

How many generations of servers look at the 2nd digit, R410 He is 11 generations.

CPU Processor:

Intel Xeon Xeon Series (gold, silver, copper)

Number of server CPUs 2 2-way IU and 2U (1u with a 1 1-way)

Thread is 1 cpu=2 thread

Maximum 2U server up to 2 paths

The relationship between CPU and core

1 CPUs are equivalent to a room, the core can be expressed as how many workers inside.

To prevent service outages:

1. Dual power supply (AB line)

2.ups (battery pack)

3. Diesel Generator + Tubing

4. An emergency oil supply agreement was signed at a nearby petrol station.

Memory:

The buffering device between the CPU and the disk is temporary storage, and the power loss data is lost.

Enterprise Case: A website solution to enhance the user experience
Write data into memory, and then write data to the hard disk either regularly or quantitatively
High concurrency Memory outage

Smes

Software that can be used with high concurrency

redis/memcached, used to write data to memory.

Enterprise Interview Question: What is the difference between buffer and cache? (Post-supplement)

Buffer Buffers Cache
Both the buffer and the cache are one area in memory
Buffer writes data to the buffer area of memory, writes buffer or is called, writes buffers
Cache buffers are read from the in-memory cache area, read cache, read caching

Disk---Permanent data storage

Mechanical HDD HDDs, home 5400 rpm, 7200 rpm, server with 10000+

Solid-State Drive SSD

HDD interface SATA (serial ATA), SAS (server Common)

SCSI high-End device interface

SAS (Serial attached SCSI)

Remember the word: Cache everywhere, computer hardware, site cluster.

At present, the largest hard disk capacity is generally 10TB, the general server can plug in 16 hard drives.

Features of RAID card disk array cards: (focus)
1. More capacity is available
2. Higher redundancy (security) available
3. Get higher performance (speed)
The three advantages of a RAID card are generally only sufficient to satisfy two of them.

Level of RAID: How to manage disks through a RAID card

Requires at least a few hard disk capacity redundancy performance
RAID 0 1 Block no loss no maximum
RAID 1 (mirroring) can only be 2 blocks wasted 1 half 100% writes slow, reads like a piece of hard disk speed

The server is generally placed in the cabinet of the machine room.

Remote control card can be installed on the server, the remote control card has the following functions
1. Remote Control and Management Server
2. Remote restart, boot, shutdown
3. Re-install the system

Remote control card for Dell server called IDRAC(remote NIC belongs to hardware)
Http://zh.community.dell.com/techcenter/w/techcenter_wiki/189.idrac-7

Summarize:
1. Operation and Maintenance responsibilities
2. Server model, size, 1u=4.45cm
3. Common Configuration
4. CPU
5. What is the difference between memory cache and buffer?
6. Program Daemon Process
7. Prevent the server from powering down
8. Raid card, RAID0 RAID1 difference
9. Disk interface, SATA home, SAS for Enterprise
10. Remote CONTROL Card

Linux Operations First Lesson