Linux disk partitioning and mounting

Linux disk partitioning and mounting

Linux partitioning

• 1. For Linux, wulun has several partitions and which directories are assigned to them. In the final analysis, it has only one root directory, an independent and unique file structure. Each partition in Linux is used to form part of the entire file system.
• 2.Linux adopts a processing method called "loading", and its entire file system contains a complete set of files and directories, and associate a partition with a directory. This means that a partition to be loaded will obtain its storage space in a directory.

• ##1. Linux hard disks are divided into IDE hard disks and SCSI hard disks. Currently, they are basically SCSI hard disks
• 2. For

  IDE hard disk, the drive identifier is "hdx~", where "hd" indicates the type of device where the partition is located, This refers to the IDE hard drive. "x" is the disk number (a is the basic disk, b is the basic slave disk, c is the auxiliary master disk, d is the auxiliary slave disk), "~" represents the partition, and the first four partitions are represented by numbers 1 to 4. They are Primary partition or extended partition, starting from 5, is a logical partition. For example, hda3 represents the third primary partition or extended partition on the first IDE hard disk, and hdb2 represents the second primary partition or extended partition on the second IDE hard disk.
• 3. For

  SCSI hard disk, it is marked as "sdx~", and the SCSI hard disk is "sd" to represent the type of device where the partition is located, and the rest is the same as the IDE hard disk (x can be abcd corresponding to the 1st, 2nd, 3rd, and 4th hard disk respectively).

View all device mounting status

Command: lsblk or lsblk -f

[root@kongchao03 ~]# lsblkNAME   MAJ:MIN RM   SIZE RO TYPE MOUNTPOINTsda      8:0    0    20G  0 disk ├─sda1   8:1    0  1023M  0 part /boot├─sda2   8:2    0    17G  0 part /└─sda3   8:3    0     2G  0 part [SWAP]sr0     11:0    1 729.9M  0 rom  /run/media/root/20210907_143734[root@kongchao03 ~]#

##Here sda1, 2, and 3 respectively represent the The first partition and the second partition of a hard disk...

Mounting case

Step 1: Create a new hard disk

Operation Step 2: Virtual machine hard disk partition

Partition instructions: fdisk /dev/sdb

• m Display command list
• p Display disk partitions the same as fdisk -l
• n Add new partition
• d Delete partition
• w Write and exit

Instructions: Enter n after starting partition, new Add a partition, then select p, and the partition type is primary partition.两次回车默认剩余全部空间，最后输入 w 写入分区并退出，若不保存退出输入 q

[root@kongchao03 ~]# fdisk /dev/sdb欢迎使用 fdisk (util-linux 2.23.2)。 > 更改将停留在内存中，直到您决定将更改写入磁盘。使用写入命令前请三思。 > Device does not contain a recognized partition table>> 使用磁盘标识符 0xdf03b737 创建新的 DOS 磁盘标签。 命令(输入 m 获取帮助)：m            命令操作   a   toggle a bootable flag   b   edit bsd disklabel   c   toggle the dos compatibility flag   d   delete a partition   g   create a new empty GPT partition table   G   create an IRIX (SGI) partition table   l   list known partition types   m   print this menu   n   add a new partition   o   create a new empty DOS partition table   p   print the partition table   q   quit without saving changes   s   create a new empty Sun disklabel   t   change a partition's system id   u   change display/entry units   v   verify the partition table   w   write table to disk and exit   x   extra functionality (experts only)命令(输入 m 获取帮助)：nPartition type:   p   primary (0 primary, 0 extended, 4 free)   e   extendedSelect (default p): p分区号 (1-4，默认 1)：1起始 扇区 (2048-2097151，默认为 2048)：将使用默认值 2048Last 扇区, +扇区 or +size{K,M,G} (2048-2097151，默认为 2097151)：将使用默认值 2097151分区 1 已设置为 Linux 类型，大小设为 1023 MiB命令(输入 m 获取帮助)：wThe partition table has been altered!Calling ioctl() to re-read partition table.正在同步磁盘。[root@kongchao03 ~]#

步骤 3：虚拟机硬盘分区格式化

格式化指令：mkfs -t ext4 /dev/sdb1

mkfs -t ext4 /dev/sdb1lsblk -f

步骤 4：将磁盘挂载到根目录下 newdisk 目录下

也可以到其他目录下挂载：将一个分区与一个目录联系起来，

mount 挂载

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挂载语法：mount 设备名称 挂载目录 （挂载目录是任意的）

[root@kongchao03 ~]# cd /
[root@kongchao03 /]# mkdir newdisk
[root@kongchao03 /]# mount /dev/sdb1 /newdisk
[root@kongchao03 /]# lsblk -f

cd 进入挂载点，在其中创建文件，实则是在分区上新建了一个文件

linux 根下的存放只是目录，真正存放数据还是在硬盘中的分区

umount 取消挂载

umount /dev/sdb1
 
lsblk -f

步骤 5：实现永久挂载（即重启不消失）

永久挂载：通过修改/etc/fstab 实现挂载

添加完成后执行mount -a 或 reboot 即可生效

[root@kongchao03 /]# vim /etc/fstab 
[root@kongchao03 /]# mount -a

df -h 查询磁盘使用情况

[root@kongchao03 ~]# df -h
文件系统        容量  已用  可用 已用% 挂载点
/dev/sda2        17G  5.8G   11G   37% /
devtmpfs        978M     0  978M    0% /dev
tmpfs           993M     0  993M    0% /dev/shm
tmpfs           993M  9.0M  984M    1% /run
tmpfs           993M     0  993M    0% /sys/fs/cgroup
/dev/sdb1       991M  2.6M  922M    1% /newdisk
/dev/sda1       991M  128M  797M   14% /boot
tmpfs           199M   20K  199M    1% /run/user/0
/dev/sr0        730M  730M     0  100% /run/media/root/20210907_143734
[root@kongchao03 ~]#

Command: du [parameter] / directory (query the disk usage of the specified directory, the default is the current directory)

参数可以联合使用示例：查询 / opt 目录的磁盘占用情况，深度为 1

[root@kongchao03 /]# cd /opt
[root@kongchao03 opt]# ls
rh
[root@kongchao03 opt]# du -h --max-depth=1 /opt
4.0K /opt/rh
8.0K /opt
[root@kongchao03 opt]#

[root@kongchao03 opt]# du -hac --max-depth=1 /opt
4.0K /opt/rh
8.0K /opt
8.0K 总用量