Linux Engineer Technology << Systems & Service Management Advanced >>

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 Engineer Technology << Systems & Service Management Advanced >>