fdisk /dev/vdb 
Command (m for help): d
--输入删除指令
--正常如果你只有一个分区输入完后再输入wq保存退出即可完成
Partition number (1-7): 1
--输入删除的分区号
Command (m for help): p
--打印分区表
Disk /dev/vdb: 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/vdb2             251         500     2008125   83  Linux
/dev/vdb3             501         750     2008125   83  Linux
/dev/vdb4             751        1305     4458037+   5  Extended
/dev/vdb5             751         875     1004031   83  Linux
/dev/vdb6             876        1000     1004031   83  Linux
/dev/vdb7            1001        1305     2449881   83  Linux
--可以看到vdb1已经被删除了
--接下来同理，删除其它分区
Command (m for help): d
Partition number (1-7): 2
 
 
Command (m for help): d
Partition number (1-7): 3
 
 
Command (m for help): d
Partition number (1-7): 4
 
 
Command (m for help): p 
 
 
Disk /dev/vdb: 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
 
 
Command (m for help): w
--保存退出
The partition table has been altered!
 
 
Calling ioctl() to re-read partition table.
Syncing disks.