fdisk 



[Mo@localhost /]$ fdisk -l

[Mo@localhost /]$ fdisk -l


为什么普通用户输入fdisk -l 命令后,没有任何的反应,没有任何的提示,

(提示权限不够等信息)不是输出磁盘的使用情况。当我切换到root用户的时候,又能够输出磁盘的使用情况:



[root@localhost ~]# fdisk -l



Disk /dev/sda: 21.5 GB, 21474836480 bytes

255 heads, 63 sectors/track, 2610 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: 0x000c88df



   Device Boot      Start         End      Blocks   Id  System

/dev/sda1   *           1          39      307200   83  Linux

Partition 1 does not end on cylinder boundary.

/dev/sda2              39        2350    18566144   83  Linux

/dev/sda3            2350        2611     2097152   82  Linux swap / Solaris



   总结:fdisk命令需要管理员的权限才能执行,在有些命令中,需要root

  权限才能够执行。



   问题:
1：（默认的情况下）有那些命令是需要root权限的?  
2：怎样做,才能使普通用户可以执行某些命令?比如说:
限制Mo用户使用vi命令
3：为什么普通用户执行fdisk命令,没有任何提示,我记得
在Linux中,命令执行成功才没有提示,执行失败有错误的信息提示.

fdisk
fdisk  [device_name] 列出指定设备的分区表，如省略device_name，则列出所有设备的分区表信息
1.查看当前分区情况
[root@localhost ~]# fdisk -l
 
Disk /dev/hda: 21.4 GB, 21474836480 bytes
15 heads, 63 sectors/track, 44384 cylinders
Units = cylinders of 945 * 512 = 483840 bytes
 
Disk /dev/hda doesn't contain a valid partition table
 
Disk /dev/sda: 21.4 GB, 21474836480 bytes
255 heads, 63 sectors/track, 2610 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
 
   Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *           1          13      104391   83  Linux
/dev/sda2              14        2610    20860402+  8e  Linux LVM
 
2.为/dev/had分区
[root@localhost ~]# fdisk /dev/hda
Device contains neither a valid DOS partition table, nor Sun, SGI or OSF disklabel
Building a new DOS disklabel. Changes will remain in memory only,
until you decide to write them. After that, of course, the previous
content won't be recoverable.
 
 
The number of cylinders for this disk is set to 44384.
There is nothing wrong with that, but this is larger than 1024,
and could in certain setups cause problems with:
1) software that runs at boot time (e.g., old versions of LILO)
2) booting and partitioning software from other OSs
   (e.g., DOS FDISK, OS/2 FDISK)
Warning: invalid flag 0x0000 of partition table 4 will be corrected by w(rite)
 
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)
 
Command (m for help): n
Command action
   e   extended
   p   primary partition (1-4)
p
Partition number (1-4): 1
First cylinder (1-44384, default 1): 1
Last cylinder or +size or +sizeM or +sizeK (1-44384, default 44384): 22192
 
Command (m for help): n
Command action
   e   extended
   p   primary partition (1-4)
e
Partition number (1-4): 2
First cylinder (22193-44384, default 22193): 22193
Last cylinder or +size or +sizeM or +sizeK (22193-44384, default 44384): 44384
 
Command (m for help): w
The partition table has been altered!
 
Calling ioctl() to re-read partition table.
Syncing disks.
 
3.查看分区后的情况
[root@localhost ~]# fdisk -l
 
Disk /dev/hda: 21.4 GB, 21474836480 bytes
15 heads, 63 sectors/track, 44384 cylinders
Units = cylinders of 945 * 512 = 483840 bytes
 
   Device Boot      Start         End      Blocks   Id  System
/dev/hda1               1       22192    10485688+  83  Linux
/dev/hda2           22193       44384    10485720    5  Extended
 
Disk /dev/sda: 21.4 GB, 21474836480 bytes
255 heads, 63 sectors/track, 2610 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
 
   Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *           1          13      104391   83  Linux
/dev/sda2              14        2610    20860402+  8e  Linux LVM
 
 

fdisk -l  查询硬盘

fdisk一般用来对硬盘分区


分区：  fdisk /dev/sdb

下面的命令知道dlmntwpq就行




在分好后，最后执行系统强制性重新读取分区信息：partprobe


格式化分区：mkfs -t ext4 /dev/sdb1


创建挂载点：mkdir /disk1


挂载：mount  /dev/sdb1  /disk1


分区的自动挂载：修改。 /etc/fstab 文件


/etc/fstab的修复，这个方法只能修复这个文件的错误：mount -o remount,rw/

linux命令fdisk用进行磁盘分区

-b 指定每个分区的大小

-l 列出指定的外围设备的分区表状况

-s 将指定的分区大小输出到标准输出上，单位为区块