Linux must-ask interview questions, cloud computing surface questions and answers

XXX Education summed up a lot of cloud computing surface questions and answers, take a look at it!

1. How does the production scenario properly partition the Linux system?

The basic principle of partitioning is simple, easy-to-use and convenient for batch management. The following recommendations are based on server role positioning:

① Standalone server: 8G memory, 300G HDD

Partition:/boot 100-200m,swap 16G, memory size 8g*2,/80g,/var 20G (also not divided),/data 180G (store web and DB data)

Advantage: The data disk and the system disk are separated, which is advantageous to the problem maintenance.

RAID scenario: Depending on the data and performance requirements, can generally be used RAID5 compromise.

② load balancer (e.g. LVS, etc.)

Partition:/boot 100-200m,swap memory 1-2 times,/,

Advantages: Simple and convenient, only a small amount of forwarding data.

RAID Scenario: Small data volume, high importance, can be used RAID1

③ RS server under load Balancing

Partition:/boot 100-200m,swap memory 1-2 times,/

Advantages: Simple and convenient, because there are many machines, the data requirements are low.

RAID Scheme: Large data volume, not high importance, performance requirements, low data requirements, can be used RAID0

④ database server MySQL and Oracle such as 16/32G memory

Partition:/Boot 100-200m,swap 16G, 1 time times of memory,/100g,/data remaining (storage DB data)

Advantages: The data disk and the system disk separate, in favor of the problem of maintenance, and maintain data integrity.

RAID scenario: Depending on the data and performance requirements The main library can take RAID10/RAID5, from which the library can use RAID0 to improve performance (in the case of read and write separations. )

⑤ Storage Server

Partition:/boot 100-200m,swap memory 1-2 times,/100g,/data (storage data)

Advantage: This server does not partition too much. Only backup, low performance requirements. capacity to be large.

RAID Scenario: SATA disk can be taken, RAID5

⑥ shared storage servers (such as NFS)

Partition:/boot 100-200m,swap memory 1-2 times,/100g,/data (storage data)

Advantage: This server does not partition too much. The Requirement for NFS shares to be more than storage is performance requirements.

RAID scenarios: Depending on performance and access requirements can be raid5,raid10, even RAID0 (to have a high-availability or dual-write solution)

⑦ Monitoring Server Cacti,nagios

Partition:/boot 100-200m,swap memory 1-2 times,/

Advantages: General importance, data requirements are also general.

RAID scenario: Flixbox or Dual-disk RAID1. Three plates on the RAID5, look at the capacity requirements of the additional disk can be.

2. Describe the principle of file deletion under Linux

The Linux system uses the number of link to control file deletion, and the file is deleted only if there is no link in the file. In general, each file has two link counters to control I_count and I_nlink. When a file is occupied by a program, I_count adds 1. I_nlink also adds 1 when the hard link of a file is one more. Deleting a file is to make this file, no process occupied, and the number of I_link is 0.

3. Please briefly describe the use of the VI editor

The ①vi editor is a basic and commonly used standard text editor for Linux systems.

The ②VI editor has three modes of operation: Normal mode, edit mode, and command mode.

③ keyboard input in normal mode any character is executed as a command, or you can enter a command to move the cursor, character, word, line copy, paste, and delete.

④ edit mode is used primarily for text input. In this mode, any characters entered by the user are saved as the contents of the file.

⑤ Command mode, the user can do some things such as String lookup, replace, display line number, etc. or must enter the command mode.

⑥ enter a colon in normal mode to enter command mode, the status line of the VI window displays a colon, waiting for the user to enter a command. "I" insert mode, which can be edited. After the user input is complete, press "ESC" and then return to normal mode, in command mode, save exit, you can use the command Wq and X. Front Plus! Indicates forced exit, forced save, and so on.

Linux must-ask interview questions, cloud computing surface questions and answers