Linux Experiment One

One or 7 questions

(1) Linux release version, kernel version; difference and contact

Kernel version: mainly Linux kernel. The core version of the serial number is composed of three parts, the form is: Major.minor.patchlecel. Where Major is the main version number, minor is the minor version number, which together form the current core version number; Patchlevel represents the number of revisions in the current version. In terms of the nature of the Linux kernel, it is only the core of the operating system, responsible for process management, file management, network management, and does not provide users with a variety of tools and application software.

To view the kernel version of the command:

Release version:

The release is a version of each company that is independently developed with its core version. Distributions typically integrate the Linux system kernel with a wide range of applications and related documents, including installation interfaces, system settings, management tools, and other software that make up a distribution suite that facilitates user use.

Common distributions are red Hat Linux/fedora Core,debian,ubantu and so on.

To view the release version of the command:

(2) The representation of hard disks and partitions in Linux

HDD Classification:

IDE,SATA,SCSI is a hard disk of three large categories, there are significant technical differences. One of the most advanced SCSI, of course, the price is more expensive. ATA, Ultra ATA, DMA, Ultra DMA and other interfaces all belong to the IDE hard disk, PATA estimate is Ultra ata. SAS, a serial-attached SCSI, is a new generation of SCSI technology.

File names for different devices under Linux:

To view the partition information command:

The letters after the SD represent different hard disks, followed by the numbers representing each partition.

To view the disk information command:

(3) file system format supported by Linux system

Linux systems support multiple different file systems, such as Ext,ext2,ext3,minix,fat,ms Dos,sysv. Currently, the main file system used by Linux is ext3.

Ext is the first file system type specifically designed for Linux, known as the extended file system, which played an important role in the early days of Linux development. Since there are many flaws in stability, speed and compatibility, ext is now rarely used. Ext2 is a scalable, high-performance file system designed to address the shortcomings of the Ext file system, known as the two scale file system. Released in 1993, Ext2 has a prominent advantage in speed and CPU utilization and is a standard file system in the Gnu/linux system that supports 256-byte long filenames with excellent file access performance. Ext3 is an upgraded version of EXT2, compatible with ext2, on the basis of ext2, added the file system logging function, known as the log file system, is the default file system for eye makeup Linux. When the log file system restarts due to power outage or other unusual events, the operating system can quickly detect and recover the file system to a normal state according to the log of the file system, and improve the recovery time of the system and improve the security of the data. If you have high security requirements for your data, it is recommended to use the Ext3 file system. Log file system is the current development direction of Linux file system

The reason why Linux systems support multiple file systems is achieved through a unified interface, which is the virtual file system (VFS).

(4) What are the installation methods of Linux system?

1, CD-ROM installation, most commonly used the most convenient method.

The disadvantage is the need to be on the edge of the machine, such as in the room, not remote control.

There is also a disadvantage is the need to have an optical drive, for the machine without optical drive is more difficult.

2,iso mirrored HDD installation, no optical drive required, cannot be re-partitioned and formatted.

3, network installation, determine the need to implement the configuration of network connectivity, high technical requirements.

4,u disk installation, download ISO image from the Internet, make boot disk installation. This is now the more popular installation method (Windows installation is also a lot of people choose this method).

(5) Primary partition, extended partition, logical partition, traditional BIOS boot +MBR vs. UEFI BIOS boot + GPT, what is the difference between partition requirements.

1. Primary partition

The primary partition is also called the boot partition, the system generally needs to be installed in this primary partition, in order to ensure that the boot automatically into the system. In simple terms, the primary partition is a disk partition that can boot the computer and read the file.

A hard disk, you can create up to 4 primary partitions at the same time, and when you have created four primary partitions, you will no longer be able to create extended partitions and logical partitions. In addition, the primary partition is independent, corresponding to the first partition on the disk, most of the current computer, in the partition, usually the C disk is divided into the primary partition.

2. Extended partition

Extended partitioning is a concept that is not actually visible on the hard disk, and cannot be used directly with extended partitions.

In addition to the primary partition, the remaining disk space is the extended partition. When a hard disk has all the capacity allocated to the primary partition, there is no expansion partition, only if the primary partition capacity is less than the hard disk capacity, the remaining space belongs to the extended partition, the extended partition can continue to expand the cut into multiple logical partitions.

3. Logical Partitioning

Above the extended partition, you can create multiple logical partitions. Logical partitions are equivalent to a block of storage, and the operating system has other logical partitions, and the primary partition has nothing to do with "standalone".

The various partitions are visually displayed.

Different points:

1, BIOS+MBR installation system requires the hard disk as long as there is a non-hidden, active primary partition can be, and UEFI+GPT require the hard disk in addition to the existence of ESP partition, there must be at least one primary partition;

2, BIOS+MBR Once the system is installed, if the system boot file in a separate partition, this partition can be visible in the operating system, you can also set this partition as hidden, the system can start normally, while the UEFI+GPT system boot file is located in the ESP partition is not visible in the operating system;

3.BIOS+MBR the primary partition of the active required activity is not unique, you can arbitrarily set a partition as the active primary partition, then the MBR can guide the operating system from this partition through the partition table, that is, you can install the operating system on any partition (primary partition whether active or extended partition), As long as there is any active primary partition, you can start the operating system from this partition, and UEFI+GPT can only place the system boot file in the ESP partition;

4.BIOS+MBR system Boot file can be the root directory of the same partition as the system files, or not the same partition as the system files, as long as the system boot file is located in the same partition as the active primary partition to start the operating system, and UEFI+GPT can only put the system boot file in the ESP partition, and the operating system must be in another primary partition, that is, UEFI+GPT mandatory system boot files and system files must be separated, not the same partition;

5. In theory, Gpt+uefi is faster than BIOS+MBR mode, but it is not obvious.

Same point:

The system boot files of 1.BIOS+MBR and uefi+gpt can be placed in separate partitions, which can be known at the 4th of the different points above;

2.BIOS+MBR system Boot file is located in the active primary partition location is not fixed, you can arbitrarily set any partition to meet this condition, the location of the UEFI+GPT ESP can be set at will, in the starting position of the hard disk, the middle position, the end, all can, as long as the partition properties and the boot file in the correct , you can boot the operating system;

The 3.BIOS+MBR system boot file is located in the same partition as the UEFI+GPT and the ESP partition can be assigned any size, not ESP must be 100M;

4.BIOS+MBR the ESP partition of a system that is not hidden, active primary, and UEFI+GPT is required to install the system, it can be set up multiple at the same time, but even if there are multiple partitions with the same properties, the Setup program is automatically written to the first one and starts from the first one.

(6) What is Mount, mount point

1. Mount:

In the Windows operating system, mounting usually means assigning a drive letter to a disk partition, including a virtual disk partition. This can be done through "Disk Management" in Computer Management.

In the Linux operating system, mounting is a very important feature that is used very frequently.

It refers to a device (typically a storage device) that is attached to an existing directory. (This directory may not be empty, but the previous content in this directory will not be available after the mount.) It should be understood that the Linux operating system sees all the devices as files and consolidates the entire computer's resources into a large file directory. To access the files in the storage device, we must attach the partition where the file resides to an existing directory and access the storage device by accessing the directory.

2. Mount point:

The mount point is actually the entry directory for the disk file system in Linux, similar to the C:, D:, E:, and so on, that are used to access different partitions in Windows.

Common mount points for 3.linux:

Catalog Content

/root directory, store system commands and user data, etc. (if the following mount points do not have separate partitions, they will be in the partition of the root directory)

/boot boot loader static link file for Linux boot-related programs

/home User directory, storing data for ordinary users

/tmp temp file

/usr is where the Linux system holds the software and, if possible, the maximum space should be allocated to it

/usr/local the self-installed program is installed here

/var constantly changing data, some server services are placed below.

/OPT Additional Application Packages

(7) partitioning scheme design for Linux system installation

1. Initial contact for novice or hard disk space Limited desktop installation recommendations:

mount point Device description

//dev/hda1 free space-swap all space after size

SWAP/DEV/HDA2 about memory size recommended at least 512MB

2. Installation recommendations for advanced user desktop:

mount point Device description

//dev/hda1 10~15g is sufficient

/home/dev/hda2 the largest remaining space

Swap/dev/hda5 approx. memory size (at least 512MB recommended)

Or

//dev/hda1 10~15g is sufficient

/home/dev/hda2 the largest remaining space

/boot/dev/hda3 100MB

Swap/dev/hda5 approx. memory size (at least 512MB recommended)

3. Installation recommendations for Advanced Server users:

mount point Device description

//dev/hda1 10~15g is sufficient

/home/dev/hda2 the largest remaining space

/boot/dev/hda3 100MB

Swap/dev/hda5 approx. memory size (at least 512MB recommended)

/var/dev/hda6 depending on the size of the server function, at least 1GB

Or

//dev/hda1 10~15g is sufficient

/home/dev/hda2 half of the largest remaining space

/boot/dev/hda3 100MB

Swap/dev/hda5 approx. memory size (at least 512MB recommended)

/var/dev/hda6 depending on the size of the server function, at least 1GB

/USR/DEV/HDA7 half of the largest remaining space

Reference blog:

1. Hard disk type and Linux partition. http://blog.csdn.net/zollty/article/details/7001950

2. The difference between hard disk partitions is introduced. Http://www.jb51.net/hardware/yingpan/394453.html

What is the difference between 3.gpt+uefi and bios+mbr? Http://www.pc841.com/article/20160729-70127.html

4. Selection of partitions for Linux system installation (recommended). Https://www.cnblogs.com/gylei/archive/2011/12/04/2275987.html

Linux Experiment One