实例(环境为: CentOS Linux release 7.2.1511 (Core), 3.10.0-327.el7.x86_64)
选择要具体操作的第二块磁盘（linux下一切是文件形式对应）：
[root@vathe ~]#fdisk /dev/sdb[root@fp-web-130 ~]# lsblk NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT sda 8:0 0 100G 0 disk ├─sda1 8:1 0 500M 0 part /boot └─sda2 8:2 0 99.5G 0 part ├─centos-root 253:0 0 95.5G 0 lvm / └─centos-swap 253:1 0 4G 0 lvm sdb 8:16 0 200G 0 disk sr0 11:0 1 1024M 0 rom loop0 7:0 0 100G 0 loop └─docker-253:0-268708167-pool 253:2 0 100G 0 dm ├─docker-253:0-268708167-edbba54df531d54ce62f43155c402a262fb51abfd1984c1ce3a765677fdd6256 253:3 0 10G 0 dm /var/lib/docker/devicemapper/mnt/edbba54df531d54ce62f43155c402a262fb51abfd loop1 7:1 0 2G 0 loop └─docker-253:0-268708167-pool 253:2 0 100G 0 dm ├─docker-253:0-268708167-edbba54df531d54ce62f43155c402a262fb51abfd1984c1ce3a765677fdd6256 253:3 0 10G 0 dm /var/lib/docker/devicemapper/mnt/edbba54df531d54ce62f43155c402a262fb51abfd
输入m可列出可以执行的命令：
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 # 删除分区
l list known partition types # 显示已知的分区类型
m print this menu # 显示帮助菜单
n add a new partition # 添加分区，包括主分区，扩展分区，逻辑分区（扩展分区中创建）
o create a new empty DOS partition table
p print the partition table # 查看分区表,很常用
q quit without saving changes # 不保存退胡
s create a new empty Sun disklabel
t change a partition's system id # 该表分区的系统id
u change display/entry units
v verify the partition table
w write table to disk and exit # 保存分区并退出
x extra functionality (experts only)查看分区表：
Command (m for help): p
Disk /dev/sdb: 10.7 GB, 10737418240 bytes
255 heads, 63 sectors/track, 1305 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x48283ee0
Device Boot Start End Blocks Id System新建一个主分区：
Command action #选择新增分区类型
e extended #扩展分区
p primary partition (1-4) #主分区
Select (default p): p // 键入p
Partition number (1-4): 1 // 键入1
First cylinder (1-1305, default 1): # 选择分区起点柱面
Using default value 1 //选择默认1
Last cylinder, +cylinders or +size{K,M,G} (1-1305, default 1305): +1G #设置分区大小1G,+表示往起点后添加，-表示往起点前添加分区查看主分区创建：
Command (m for help): p
Disk /dev/sdb: 10.7 GB, 10737418240 bytes # 磁盘总大小 10.7GB
255 heads, 63 sectors/track, 1305 cylinders # 255个磁头，每个磁道63个扇区，1305个圆柱面
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x48283ee0
Device Boot Start End Blocks Id System
/dev/sdb1 1 132 1060258+ 83 Linux
建立一个扩展分区Command (m for help):n //输入n回车
Partition type:
p primary (0 primary, 0 extended, 4 free)
e extended
Select (default p): p #输入p表示创建主分区,回车
Partition number (1-4): 1 #分区号为1，分区号是1到4,我们这里输入1,回车
First sector (2048-419430399, default 2048): #直接回车默认从第一个柱面开始划分，默认分区起始位置是从2048开始
Using default value 2048
First sector (2048-419430399, default 2048): 2048
Last sector, +sectors or +size{K,M,G} (2048-419430399, default 419430399): 69905066 //这里直接默认回车将
全部都分配给当前创建的主分区，这里肯定不想，所以需要这里设置一个值,我用计算器419430399/6=69905066
Partition 1 of type Linux and of size 33GiB is set
Command (m for help): p //这时再次出现提示: 这里输入p,查看创建情况
Disk /dev/sdb: 214.7 GB, 214748364800 bytes, 419430400 sectors //硬盘整个的信息
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk label type: dos
Disk identifier: 0xbd1a05e2
Device Boot Start End Blocks Id System
/dev/sdb1 2048 69905066 34951509+ 83 Linux
注： 每次操作完毕，就会回到 Command (m for help): 提示让你继续操作。
在扩展分区中创建一个逻辑分区
Command (m for help):n
Partition type:
p primary (1 primary, 0 extended, 3 free)
e extended
Select (default p):e //输入e,表示要创建扩展分区
Partition number (2-4, default 2):2 //输入2回车，开始创建继续扩展分区
First sector (69905067-419430399, default 69906432): //这里我直接回车
Using default value 69906432： Last sector, +sectors or +size{K,M,G} (69906432-419430399, default 419430399): //这里也直接回车，表示把剩下的部分都划给扩展分区
Using default value 419430399
Partition 2 of type Extended and of size 166.7 GiB is set(这里翻译为分区2为扩展分区，大小为166.7G被设置)
查看分区列表
Command (m for help): p //出现提示，输入p查看当前创建情况
Disk /dev/sdb: 214.7 GB, 214748364800 bytes, 419430400 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
Disk label type: dos
Disk identifier: 0xbd1a05e2
Device Boot Start End Blocks Id System
/dev/sdb1 2048 69905066 34951509+ 83 Linux
/dev/sdb2 69906432 419430399 174761984 5 Extended
保存退出
Command (m for help): w # 保存退出
The partition table has been altered!
Calling ioctl() to re-read partition table.
Syncing disks.分区成功，当然，要使用磁盘，还需要进行两部操作，才能使用磁盘——将磁盘挂载在具体目录（或文件），和对个分区进行格式化，最后结果如下。
请参考我的另一篇文章 linux磁盘分区fdisk命令操作（实践）详细版：