Linux磁盘分区
Linux的磁盘分区工具有两种，一种是fdisk，一种是parted，
fdisk只能用来进行2T以下的磁盘分区，而parted可以进行2T以上的磁盘分区
MBR分区表：Master Boot Record，即硬盘主引导记录分区表，只支持容量在 2.1TB 以下的硬盘，超过2.1TB的硬盘只能管理2.1TB，最多只支持4个主分区或三个主分区和一个扩展分区，扩展分区下可以有多个逻辑分区。
GPT分区表：GPT，全局唯一标识分区表(GUID Partition Table)，与MBR最大4个分区表项的限制相比，GPT对分区数量没有限制，但Windows最大仅支持128个GPT分区，GPT可管理硬盘大小达到了18EB。只有基于UEFI平台的主板才支持GPT分区引导启动。
fdisk
注意，实验环境为Centos8
交互式命令
fdisk device_path
shell
[root@localhost ~]# fdisk /dev/sdb
Welcome to fdisk (util-linux 2.32.1).
Changes will remain in memory only, until you decide to write them.
Be careful before using the write command.
Device does not contain a recognized partition table.
Created a new DOS disklabel with disk identifier 0x3be3d17c.
Command (m for help): m
Help:
DOS (MBR)
a toggle a bootable flag
b edit nested BSD disklabel
c toggle the dos compatibility flag
Generic
d delete a partition
F list free unpartitioned space
l list known partition types
n add a new partition
p print the partition table
t change a partition type
v verify the partition table
i print information about a partition
Misc
m print this menu
u change display/entry units
x extra functionality (experts only)
Script
I load disk layout from sfdisk script file
O dump disk layout to sfdisk script file
Save & Exit
w write table to disk and exit
q quit without saving changes
Create a new label
g create a new empty GPT partition table
G create a new empty SGI (IRIX) partition table
o create a new empty DOS partition table
s create a new empty Sun partition table在使用m后，会打印出相关的信息，有些不需要关注，在这里写一些需要关注的命令
d delete a partition // 删除一个分区
F list free unpartitioned space //列出未分区的空间
l list known partition types //显示已知的分区类型，其中82为Linux swap分区，83为Linux分区
n add a new partition // 增加一个新的分区
p print the partition table //显示磁盘当前的分区表
t change a partition type //改变一个分区的系统ID，就是改变分区类型
v verify the partition table //验证磁盘分区表
i print information about a partition //打印分区表信息
w write table to disk and exit //将分区表写入磁盘并退出（保存并退出）
q quit without saving changes //不保存分区表信息下面的步骤根据提示进行就可以了
实例
c
[root@localhost ~]# fdisk /dev/sdb
Welcome to fdisk (util-linux 2.32.1).
Changes will remain in memory only, until you decide to write them.
Be careful before using the write command.
Device does not contain a recognized partition table.
Created a new DOS disklabel with disk identifier 0x2a38366a.
Command (m for help): p
Disk /dev/sdb: 100 GiB, 107374182400 bytes, 209715200 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos //这里的dos就是对应的mbr
Disk identifier: 0x2a38366a
Command (m for help): n
Partition type
p primary (0 primary, 0 extended, 4 free)
e extended (container for logical partitions)
Select (default p): p //选择的分区是主分区
Partition number (1-4, default 1):
First sector (2048-209715199, default 2048):
Last sector, +sectors or +size{K,M,G,T,P} (2048-209715199, default 209715199): +10G //表示分区大小
Created a new partition 1 of type 'Linux' and of size 10 GiB.
Command (m for help): n
Partition type
p primary (1 primary, 0 extended, 3 free)
e extended (container for logical partitions)
Select (default p): p
Partition number (2-4, default 2):
First sector (20973568-209715199, default 20973568):
Last sector, +sectors or +size{K,M,G,T,P} (20973568-209715199, default 209715199): +60G
Created a new partition 2 of type 'Linux' and of size 60 GiB.
Command (m for help): p
Disk /dev/sdb: 100 GiB, 107374182400 bytes, 209715200 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0x2a38366a
Device Boot Start End Sectors Size Id Type
/dev/sdb1 2048 20973567 20971520 10G 83 Linux
/dev/sdb2 20973568 146802687 125829120 60G 83 Linux
Command (m for help): w //注意需要将修改保存，不然就是白改的
The partition table has been altered.
Calling ioctl() to re-read partition table.
Syncing disks.parted
分为两种方式，交互式和非交互式，两种方式其实差不多。在parted操作是立即生效的，不需要进行保存，请谨慎操作！！！
[root@localhost ~]# parted /dev/sdb
GNU Parted 3.2
Using /dev/sdb
Welcome to GNU Parted! Type 'help' to view a list of commands.
(parted) help
align-check TYPE N check partition N for TYPE(min|opt) alignment
help [COMMAND] print general help, or help on COMMAND
mklabel,mktable LABEL-TYPE create a new disklabel (partition table)
mkpart PART-TYPE [FS-TYPE] START END make a partition
name NUMBER NAME name partition NUMBER as NAME
print [devices|free|list,all|NUMBER] display the partition table, available devices, free space, all found partitions, or a particular partition
quit exit program
rescue START END rescue a lost partition near START and END
resizepart NUMBER END resize partition NUMBER
rm NUMBER delete partition NUMBER
select DEVICE choose the device to edit
disk_set FLAG STATE change the FLAG on selected device
disk_toggle [FLAG] toggle the state of FLAG on selected device
set NUMBER FLAG STATE change the FLAG on partition NUMBER
toggle [NUMBER [FLAG]] toggle the state of FLAG on partition NUMBER
unit UNIT set the default unit to UNIT
version display the version number and copyright information of GNU Parted需要使用的命令有几个：
mklabel //用来进行生成分区表
mkpart //用来制作分区
print //打印相关信息
rm //删除分区
select //切换操作的磁盘生成分区表
(parted) mklabel gpt生成分区
mkpart PART-TYPE [FS-TYPE] START END
Warning: The resulting partition is not properly aligned for best performance: 34s % 2048s != 0s
注意，在生成分区时，START需要选择0%或者1M开始,不然会出现以上错误。例如：
mkpart primary xfs 1M 10G or mkpart primary xfs 0% 10G
查看
print list //打印主机上所有设备的分区表
print free //打印空余空间
print //打印正在进行操作的磁盘的分区表删除
rm <指定的分区编号>实例
c
[root@localhost ~]# parted /dev/sdb
GNU Parted 3.2
Using /dev/sdb
Welcome to GNU Parted! Type 'help' to view a list of commands.
(parted) mklabel gpt //生成Gpt分区表
(parted) mkpart primary xfs 1M 10G //生成一个主分区，大小为10G，文件系统为xfs
(parted) mkpart primary ext4 10G 50G //生成一个主分区，大小为40G，文件系统为ext4
(parted) print
Model: VMware Virtual disk (scsi)
Disk /dev/sdb: 107GB
Sector size (logical/physical): 512B/512B
Partition Table: gpt
Disk Flags:
Number Start End Size File system Name Flags
1 1049kB 10.0GB 9999MB xfs primary //可以看到这两个分区
2 10.0GB 50.0GB 40.0GB ext4 primary
(parted) rm 1 //这里的1是，上面的Number的序号
(parted) print //删除之后可以看到，第一个分区已经被删除
Model: VMware Virtual disk (scsi)
Disk /dev/sdb: 107GB
Sector size (logical/physical): 512B/512B
Partition Table: gpt
Disk Flags:
Number Start End Size File system Name Flags
2 10.0GB 50.0GB 40.0GB ext4 primary
(parted) print free //可以看到空闲的空间
Model: VMware Virtual disk (scsi)
Disk /dev/sdb: 107GB
Sector size (logical/physical): 512B/512B
Partition Table: gpt
Disk Flags:
Number Start End Size File system Name Flags
17.4kB 10.0GB 10.0GB Free Space
2 10.0GB 50.0GB 40.0GB ext4 primary
50.0GB 107GB 57.4GB Free Spaceparted不需要使用partprobe通知操作系统