有关fdisk的相关介绍：
fdisk 的说明
当我们通过 fdisk 设备，进入相应设备的操作时，会发现有如下的提示；以 fdisk /dev/sda 设备为例，以下同；
[root@localhost beinan]# fdisk /dev/sda
Command (m for help): 在这里按m ，就会输出帮助；
Command action
a toggle a bootable flag
b edit bsd disklabel
c toggle the dos compatibility flag
d delete a partition 注：这是删除一个分区的动作；
l list known partition types 注：l是列出分区类型，以供我们设置相应分区的类型；
m print this menu 注：m 是列出帮助信息；
n add a new partition 注：添加一个分区；
o create a new empty DOS partition table
p print the partition table 注：p列出分区表；
q quit without saving changes 注：不保存退出；
s create a new empty Sun disklabel
t change a partition’s system id 注：t 改变分区类型；
u change display/entry units
v verify the partition table
w write table to disk and exit 注：把分区表写入硬盘并退出；
x extra functionality (experts only) 注：扩展应用，专家功能；
1. 添加磁盘，查看磁盘状况
[root@db1 /]# fdisk -l
Disk /dev/sda: 10.7 GB, 10737418240 bytes
255 heads, 63 sectors/track, 1305 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/sda1 * 151 1305 9277537+ 83 Linux
/dev/sda2 1 150 1204843+ 82 Linux swap
Partition table entries are not in disk order
Disk /dev/sdb: 5368 MB, 5368709120 bytes
255 heads, 63 sectors/track, 652 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
从查询结果看出，多了一个/dev/sdb的盘
2. 用fdisk 对/dev/sdb 进行分区
[root@db1 /]# fdisk /dev/sdb
Command (m for help): n
Command action
e extended
p primary partition (1-4)
p
Partition number (1-4): 1
First cylinder (1-652, default 1):
Using default value 1
Last cylinder or +size or +sizeM or +sizeK (1-652, default 652):
Using default value 652
Command (m for help): w
The partition table has been altered!
Calling ioctl() to re-read partition table.
Syncing disks.
再次查看分区情况，多出来一个/dev/sdb1 的区，这个1是我们在前面指定的，如果我们指定2，就变成 sdb2了。
[root@db1 /]# fdisk -l
Disk /dev/sda: 10.7 GB, 10737418240 bytes
255 heads, 63 sectors/track, 1305 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/sda1 * 151 1305 9277537+ 83 Linux
/dev/sda2 1 150 1204843+ 82 Linux swap
Partition table entries are not in disk order
Disk /dev/sdb: 5368 MB, 5368709120 bytes
255 heads, 63 sectors/track, 652 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Device Boot Start End Blocks Id System
/dev/sdb1 1 652 5237158+ 83 Linux
[root@db1 /]#
如果创建完之后，/proc/partitions 查看不到对应的分区，使用parprobe 命令刷新一下就可以了：
[root@web1 ~]# cat /proc/partitions
major minor #blocks name
8 0 175825944 sda
8 1 1020096 sda1
8 2 30716280 sda2
8 3 8193150 sda3
[root@web1 ~]# partprobe /dev/sda
[root@web1 ~]# cat /proc/partitions
major minor #blocks name
8 0 175825944 sda
8 1 1020096 sda1
8 2 30716280 sda2
8 3 8193150 sda3
8 4 135893835 sda4
[root@web1 ~]#
