命令简介
fdisk 命令用于查看磁盘使用情况和磁盘分区，它可用于创建，删除和修改磁盘分区。
语法格式
代码语言：javascript复制disk [-uc] [-b sectorsize] [-C cyls] [-H heads] [-S sects] device
选项说明
代码语言：javascript复制-b <大小> #扇区大小(512、1024、2048或4096)
-c[=<模式>] #兼容模式：“dos”或“nondos”(默认)
-h #打印此帮助文本
-u[=<单位>] #显示单位：“cylinders”(柱面)或“sectors”(扇区，默认)
-v #打印程序版本
-C <数字> #指定柱面数
-H <数字> #指定磁头数
-S <数字> #指定每个磁道的扇区数
应用举例
选择要进行操作的磁盘
代码语言：javascript复制[root@localhost ~]$ fdisk /dev/sdb
输入 m 查看可执行的命令
代码语言：javascript复制command (m for help): m
Command action
a toggle a bootable flag
b edit bsd disklabel
c toggle the dos compatibility flag
d delete a partition
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)
输入 p 列出磁盘目前的分区情况
代码语言：javascript复制Command (m for help): p
Disk /dev/sdb: 3221 MB, 3221225472 bytes
255 heads, 63 sectors/track, 391 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/sdb1 1 1 8001 8e Linux LVM
/dev/sdb2 2 26 200812 83 Linux
输入 d 然后选择分区，删除现有分区
代码语言：javascript复制Command (m for help): d
Partition number (1-4): 1
Command (m for help): d
Selected partition 2
查看分区情况，确认分区已经删除
代码语言：javascript复制Command (m for help): print
Disk /dev/sdb: 3221 MB, 3221225472 bytes
255 heads, 63 sectors/track, 391 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
Command (m for help):
输入 n 建立新的磁盘分区，首先建立两个主磁盘分区
代码语言：javascript复制Command (m for help): n
Command action
e extended
p primary partition (1-4)
p #建立主分区
Partition number (1-4): 1 #分区号
First cylinder (1-391, default 1): #分区起始位置
Using default value 1
last cylinder or size or sizeM or sizeK (1-391, default 391): 100 #分区结束位置，单位为扇区
Command (m for help): n #再建立一个分区
Command action
e extended
p primary partition (1-4)
p
Partition number (1-4): 2 #分区号为2
First cylinder (101-391, default 101):
Using default value 101
Last cylinder or size or sizeM or sizeK (101-391, default 391): 200M #分区结束位置，单位为M
确认分区建立成功
代码语言：javascript复制Command (m for help): p
Disk /dev/sdb: 3221 MB, 3221225472 bytes
255 heads, 63 sectors/track, 391 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/sdb1 1 100 803218 83 Linux
/dev/sdb2 101 125 200812 83 Linux
再建立一个逻辑分区
代码语言：javascript复制Command (m for help): n
Command action
e extended
p primary partition (1-4)
e #选择扩展分区
Partition number (1-4): 3
First cylinder (126-391, default 126):
Using default value 126
Last cylinder or size or sizeM or sizeK (126-391, default 391):
Using default value 391
确认扩展分区建立成功
代码语言：javascript复制Command (m for help): p
Disk /dev/sdb: 3221 MB, 3221225472 bytes
255 heads, 63 sectors/track, 391 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/sdb1 1 100 803218 83 Linux
/dev/sdb2 101 125 200812 83 Linux
/dev/sdb3 126 391 2136645 5 Extended
在扩展分区上建立两个逻辑分区
代码语言：javascript复制Command (m for help): n
Command action
l logical (5 or over)
p primary partition (1-4)
l #选择逻辑分区
First cylinder (126-391, default 126):
Using default value 126
Last cylinder or size or sizeM or sizeK (126-391, default 391): 400M
Command (m for help): n
Command action
l logical (5 or over)
p primary partition (1-4)
l
First cylinder (176-391, default 176):
Using default value 176
Last cylinder or size or sizeM or sizeK (176-391, default 391):
Using default value 391
确认逻辑分区建立成功
代码语言：javascript复制Command (m for help): p
Disk /dev/sdb: 3221 MB, 3221225472 bytes
255 heads, 63 sectors/track, 391 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/sdb1 1 100 803218 83 Linux
/dev/sdb2 101 125 200812 83 Linux
/dev/sdb3 126 391 2136645 5 Extended
/dev/sdb5 126 175 401593 83 Linux
/dev/sdb6 176 391 1734988 83 Linux
Command (m for help):
保存操作信息
代码语言：javascript复制Command (m for help): w
The partition table has been altered!
Calling ioctl() to re-read partition table.
Syncing disks.
建立好分区之后我们还需要对分区进行格式化才能在系统中使用磁盘。这个格式化命令后面的章节会给大家进行详细讲解。
