Linux Cloud Computing-Phase 2-essential knowledge

Linux Administrator Technology--

01. Wildcard characters * 、?、 [], {} function

*: Any number of arbitrary characters

?: Single Character

[A-Z]: one of multiple characters or continuous range, omitted if none

{A,MIN,XY}: Multiple sets of different strings, full match

02. Use NMCLI to create a new connection and configure it with parameters such as a static IP address

# NMCLI Connection Add Con-name "Connection name" ifname "Interface name" type Ethernet

# NMCLI Connection Modify "Connection name" Ipv4.method manual ipv4.address "IP address/Mask length

Default Gateway "

# NMCLI Connection Modify "Connection name" Ipv4.dns DNS server address Connection.autoconnect Yes

# NMCLI Connection up "connection name"

03. Specify the available Yum software sources for Red Hat series Linux hosts

# vim/etc/yum.repos.d/file name. Repo

[Warehouse ID]

Name = Warehouse Description text

BaseURL = Access address of the warehouse

Gpgcheck = 0

What is the difference between an LDAP user account and an ordinary system user account?

LDAP User: belongs to the network account, its login name, password stored on the other server

Ordinary system User: belong to the local account, its login name, password stored in the system/etc/passwd,/etc/shadow

and other documents.

05. When you use Crontab to edit a scheduled task, the format of each task record is composed

Minute hour date Month week

Task command line

What are the characteristics of the MSDOS partition mode, how to use the Fdisk tool to adjust the partition table of the hard disk

MSDOS partition mode: Can divide 1~4 primary partition, or 0~3 primary partition + an extended partition (n logical partition),

Operation of the disk <2.2TB

# fdisk

/dev/Disk Name

Main operation instructions: n New, D Delete, P view partition table, W save exit, Q do not save exit

How the LVM logical Volume storage scheme is implemented, with the use of the main command tools

LVM Storage Scheme: 1 or more scattered storage devices (physical volumes) = = "integrated into larger virtual disks (volume group) = ="

The virtual partition (logical volume) is then divided into the virtual disk, the main advantages: device peers, capacity dynamic scaling

Main command tools:

#

#

#

#

Vgcreate

Vgextend

Lvcreate

Lvextend

Volume group name physical storage device ...

Volume group name newly added physical storage device ...

-L size-N Logical Volume name volume group name

-L New Size/dev/Volume group name/Logical volume name

08. What is the role of swap space?

Swap space can use a portion of the hard disk space to simulate memory and alleviate the problem of insufficient physical memory

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Linux Engineer Technology--

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01. Command alias function, set a permanent valid command alias

The role of aliases: Create a shorter, better-written command word for a lengthy command line that requires frequent use

# VIM/ETC/BASHRC

Alias aliases = ' Actual command line '

02. Red Hat 7 Series Firewall service preset security zone public, trusted, drop functions and features

Public zone: The default zone, only allow SSH services for native, others deny

Trusted zone: Any access to this machine is allowed

Drop zone: Any packets that access this computer will be rejected

What is SELinux and how does it affect the Linux system?

SELinux mechanism: A kernel-based security enhancement mechanism that provides a set of documents, processes, and other objects in a Linux system

Pre-set protection rules

Impact on Linux systems: In a forced protected mode, even root cannot violate its protection rules (unless changing

or avoidance rules)

04. Quickly add a new virtual host when you configure the HTTPD Web server

1) Create a separate configuration file for each virtual host, put it in the/etc/httpd/conf.d/directory, configure the file

Name ends with. conf

2) Configure <virtualhost IP Address: Port number >. .. </VirtualHost> section tags, where statements are used

ServerName Specify the site name, use DocumentRoot to specify the Web page directory

3) Then restart the httpd service

05. Conditions for erecting a secure Web site based on httpd

Installing the Mod_ssl module package

Provide the available Web site certificates, keys, and deploy to the correct location

Modify the/etc/httpd/conf.d/ssl.conf configuration file to specify the site name, Web directory, certificate, and path to the key

06. Dynamic Web page and static Web page difference, based on httpd to support PHP program, Python program needs to have the conditions

Static Web page: The Web page file accessed by the browser is the Web page file provided by the server.

Dynamic Web page: Web page file accessed by the browser is a dynamically generated Web page file by a program specified by the server

Support PHP Program: Install httpd, PHP package

Support for Python programs: Install HTTPD, MOD_WSGI packages, and add program call aliases when configuring a site

(Wsgiscriptalias)

What is NFS referring to, the main difference from EXT4, XFS

Nfs,network File System: Document resources reside on other hosts ' directories, network filesystem

EXT4, XFS: The document resource is stored on a device that has a well-formatted partition on the computer, and the local file system

08. What are shell scripts and what are the benefits of using shell scripts?

Shell script: A collection of a number of command-line, able to complete a specific task, can be executed in order to repeat the execution of files

The benefits of Shell scripting: process repetitive tasks, simplify complex tasks, and automate tasks that are manually intervened

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System & Service Management Advanced--

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01. What are the roles and advantages of virtualization

Role: Integrate one or more sets of physical resources into a platform to virtualize more available computer resources in a software way

Advantages: To change more, save costs, resource scheduling more flexible, improve efficiency

02. When setting access permissions for a document, the values 777, 755, 700, 644, 600, 000 each indicate what permissions

777

755

700

644

600

000

= = "Rwxrwxrwx

= = "Rwxr-xr-x

= = "rwx------

= = "rw-r--r--

= = "RW-------

= = "---------

03. Description of the Linux directory/,/boot,/home,/root,/bin,/dev,/etc usage

/: root directory of the entire Linux file system

/boot: Store the system kernel, boot menu configuration and other files

/home: Default family directory for normal users (subdirectories with the same name)

/root: Administrator's home directory

/bin,/sbin: Storage System command, executable program

/dev: Store various device files

/etc: Store various system configuration, system service configuration file

04. Briefly describe the basic process of installing software from source code, and the purpose of each link, command tools

Tar Unpack: Extract the downloaded source package to release

./configure configuration: Set up the Installation checklist (Specify the installation directory, required features, etc.)

Make compile: The source code files are made into binary executable program files or related modules according to the installation manifest

Make install Installation: Install executables, related modules, configurations, documents, etc. into the system

What does the RAID array mean, RAID0, RAID1, RAID10, RAID5, RAID6 characteristics of the different levels

RAID0: Stripe mode, at least 2 disks, improves efficiency through concurrent read and write

RAID1: Mirrored mode, at least 2 disks, improves disk device reliability with mirrored backups

RAID10: Condition + mirroring mode, equivalent to RAID1+RAID0, at least 4 disks, higher read and write efficiency and reliability

RAID5: Cost-effective mode, at least 3 disks, of which 1 disk capacity is used to store recovery checksum data

RAID6: Equivalent to an extended version of RAID5, at least 4 disks, of which 2 disk capacity is used to store recovery checksum data

The role of the DNS server, the difference between authoritative DNS, cache DNS, and the rapid setting up of a cache DNS server

The role of the DNS server: to provide clients with "domain name-->IP address" Information Query service

Authoritative DNS: Responsible for at least one DNS zone, authorized by the Internet Domain name Authority, to provide only a small number of domain names query

Cache DNS: Does not require any DNS zones, no authorization, but can proxy client requests to query for almost all

Domain name

07. Brief description of how DNS separation resolution works, key configuration

DNS Separation Resolution: Provides different parsing results for different clients for the same domain name

Key configuration: The client is categorized by a view statement, using Match-client in each view to match the client's

Source addresses, each of which defines a destination DNS zone but calls a different address library file

08. What are the requirements for a PXE network batch installation, the role of each component, and how to implement unattended installations

DHCP Server: Provide the client with parameters such as IP address, and inform the next server address, startup file name

TFTP Server: Provides the client with boot files, boot menu configuration, kernel to install the system, and initial image files

Repositories: Provides installation tree resources for clients via HTTP or FTP (RHEL7 disc directory structure)

Implement Kickstart unattended Installation:

1) Prepare an answer list (i.e. answer file) for the questions involved in the installation process in advance

2) Then deploy this file to a location that the client can download

3) by modifying the boot configuration of the pxelinux.0 to enable the client to automatically invoke the answer file to implement polygon interaction when loading the system

Linux Cloud Computing-Phase 2-essential knowledge