Linux operations First lesson----server hardware

first, the server hardware introduction

1. Unit (server thickness, height): U 1u==4.45cm

2. Type of server: Rack server, Blade server, Tower server

3. Server Model:

1u

2u

2010 formerly	1850/1950	2850/2950
2010--2013	r410/r610	r710
2013--2016	r720/r730

4. Algebraic problems with the server: pure numbers generally look at numbers from left to right number second digit is a few (for example:1850), is the first generation (8 generation), there are letters, also from left to right number second digit (example R710), and then add 10 to this number, is algebra ( one).

5. Power: Some high-configuration servers with important data need dual power supply, also known as AB Road; The general server is a single power supply. The large number of Watts is not recommended for home use.

Second, the CPU of the server

1. model:Intel exon series

2. Quantity: General 2/4, also known as 2 way/4 road.

3. Core: General 4-Core, the latest server can reach 6, 8, 10, 12 cores.

Third, the memory of the server

1. Size: 16g-256g

2. program code, process, daemon: program code equivalent to software, programs, processes are running programs, daemons are running programs.

3. Example:

(1) High Concurrency: Write customer command information to memory, then to disk, alleviate write disk speed pressure.

There is not enough memory (there is more than one server in the enterprise, so there is no memory problem).

Prevent power outages (once power is lost, information that is not yet written to disk in memory will be missing):

Dual power supply (AB Road), different Transformers

Diesel Generator + oil tank

UPS (uninterruptible power supply) battery pack, which lasts for half an hour or one hours, is sufficient to transfer in-memory information.

(2) SME: Write information directly to the hard disk

4.buffer and Cache (two regions in the hard drive)

Buffer: buffers, data into the buffer area of the hard disk, write buffer, also known as "Write buffer"

Cache: Cache, data is read in the cache, read cache, also known as "read buffer"

Four, the server's hard disk

1. Type: Mechanical hard drives, solid-state drives (SSDs)

2. Interface: SATA (Normal interface), SCSI (high-end Device interface), SAS (SATA attached SCSI)

3.raid Card (disk array card)

Features: Higher capacity

Higher redundancy

Higher performance

4. How to control the disk via the RAID card:

	Need at least	Capacity	Redundancy	Performance
RAID 1	1	The sum of all disks	No	High
Raid 2	only 2 bucks.	Half the sum of all the disks	100%	Equivalent to the speed of reading a piece of disk

5. The role of the remote control card:

Remote control and Management Server

Remote server shutdown, boot, restart

Re-assembly system

Linux operations First lesson----server hardware