1.说明:fdisk如何来学习
fdisk,就是在linux中用来分区的一个命令了,至于详细的参数,可以man一下,这里给出实际应用过程中最常用的用法,因为这样比起单纯讲命令的语法功能更能掌握一个命令的实际用法。
下面的过程是在我自己的实验环境中搭建,先把简要的过程看一下:
(1)添加一块1GB的磁盘
(2)fdisk详细分区过程
(3)通知Linux内核分区信息的更改
(4)格式化分区
(5)挂载分区
OK!我相信这样一个过程下来,你是真正可以做到添加一块硬盘,并自己做分区格式化以及使用,这样的话,意义就真的比单纯讲fdisk的语法参数要好得多了!
2.实战演示:从添加硬盘到真正可以使用硬盘
(1)添加一块1GB的磁盘
我是在虚拟机环境下直接添加的,方法很简单,这里就不多说了,下面给出在linux下查看该硬盘的信息:
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[root@xpleaf ~]# fdisk -l /dev/sdb Disk /dev/sdb: 1073 MB, 1073741824bytes
255 heads, 63 sectors/track, 130cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes/ 512 bytes
Disk identifier: 0x00000000
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(2)fdisk详细分区过程
下面直接给出详细过程,重要的一些说明在该过程中已经给出,注意看了:
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[root@xpleaf ~]# fdisk /dev/sdb ===>直接接磁盘名就可以分区 Device contains neither a valid DOSpartition table, nor Sun, SGI or OSF disklabel Building a new DOS disklabel with diskidentifier 0x7f3aa9cb .
Changes will remain in memory only,until you decide to write them.
After that, of course, the previouscontent won't be recoverable. Warning: invalid flag 0x0000 ofpartition table 4 will be corrected by w(rite)
WARNING: DOS-compatible mode isdeprecated. It's strongly recommended to switch off the mode (command 'c' ) andchange display units to
sectors (command 'u' ).
Command (m for help): m
Command action a toggle a bootable flag
b edit bsd disklabel
c toggle the dos compatibilityflag
d delete a partition ===>删除一个分区
l list known partition types ===>查看分区类型对应编号列表
m print this menu ===>打印此帮助菜单
n add a new partition ===>新建一个分区
o create a new empty DOSpartition table
p print the partition table ===>打印分区表
q quit without saving changes ===>退出但不保存更改
s create a new empty Sundisklabel
t change a partition's system id ===>更改分区类型(做LVM时需要)
u change display/entry units
v verify the partition table
w write table to disk and exit ===>将操作写入分区表并退出程序
x extra functionality (expertsonly)
Command (m for help): n
Command action e extended
p primary partition ( 1 - 4 )
p ===>新建一个主分区 Partition number ( 1 - 4 ): 1 ===>指定主分区的分区号码
First cylinder ( 1 - 130 , default 1 ): ===>指定分区开始的柱面号
Usingdefault value 1
Last cylinder, +cylinders or+size{K,M,G} ( 1 - 130 , default 130 ): +100M
===>指定分区结束的柱面号,或者指定分区大小,让fdisk自动判断结束柱面号 Command (m for help): p
Disk /dev/sdb: 1073 MB, 1073741824bytes
255 heads, 63 sectors/track, 130cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes/ 512 bytes
Disk identifier: 0x7f3aa9cb
Device Boot Start End Blocks Id System
/dev/sdb1 1 14 112423 + 83 Linux
Command (m for help): n
Command action e extended
p primary partition ( 1 - 4 )
e ===>新建一个扩展分区 Partition number ( 1 - 4 ): 1
Partition 1 is already defined. Delete it before re-adding it.
===>由于前面已经使用了分区号码 1 ,所以这里会提示错误
Command (m for help): n
Command action e extended
p primary partition ( 1 - 4 )
e Partition number ( 1 - 4 ): 2
First cylinder ( 15 - 130 , default 15 ):
Usingdefault value 15
Last cylinder, +cylinders or+size{K,M,G} ( 15 - 130 , default 130 ):
Usingdefault value 130
===>分区的开始柱面号和结束柱面号都使用默认值,即把剩余磁盘空间分配给该分区 Command (m for help): p
Disk /dev/sdb: 1073 MB, 1073741824bytes
255 heads, 63 sectors/track, 130cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes/ 512 bytes
Disk identifier: 0x7f3aa9cb
Device Boot Start End Blocks Id System
/dev/sdb1 1 14 112423 + 83 Linux
/dev/sdb2 15 130 931770 5 Extended
Command (m for help): n
Command action l logical ( 5 or over) ===>由于扩展分区只能有一个,上面新建扩展分区后
p primary partition ( 1 - 4 ) 这里就显示逻辑分区了,也可以看到fdisk命令,
p 要想新建逻辑分区,需要先新建扩展分区 Partition number ( 1 - 4 ): 3
No free sectors available ===>这里还想再新建一个主分区,但是提示已经没有磁盘空间剩余 Command (m for help): n
Command action l logical ( 5 or over)
p primary partition ( 1 - 4 )
l ===>新建一个逻辑分区 First cylinder ( 15 - 130 , default 15 ):
Usingdefault value 15
Last cylinder, +cylinders or+size{K,M,G} ( 15 - 130 , default 130 ): +400M
Command (m for help): p
Disk /dev/sdb: 1073 MB, 1073741824bytes
255 heads, 63 sectors/track, 130cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes/ 512 bytes
Disk identifier: 0x7f3aa9cb
Device Boot Start End Blocks Id System
/dev/sdb1 1 14 112423 + 83 Linux
/dev/sdb2 15 130 931770 5 Extended
/dev/sdb5 15 66 417658 + 83 Linux
Command (m for help): n
Command action l logical ( 5 or over)
p primary partition ( 1 - 4 )
l First cylinder ( 67 - 130 , default 67 ):
Usingdefault value 67
Last cylinder, +cylinders or+size{K,M,G} ( 67 - 130 , default 130 ):
Usingdefault value 130
Command (m for help): p
Disk /dev/sdb: 1073 MB, 1073741824bytes
255 heads, 63 sectors/track, 130cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes/ 512 bytes
Disk identifier: 0x7f3aa9cb
Device Boot Start End Blocks Id System
/dev/sdb1 1 14 112423 + 83 Linux
/dev/sdb2 15 130 931770 5 Extended
/dev/sdb5 15 66 417658 + 83 Linux
/dev/sdb6 67 130 514048 + 83 Linux
Command (m for help): w ===>保存更改
The partition table has been altered! Calling ioctl() to re-read partitiontable. Syncing disks. |
OK,可以看到,fdisk的分区方法是非常简单的,但是前提就是需要你得对硬盘的知识有一定的了解,比如:硬盘的内部结构、磁头、柱面、扇区等,这些知识都需要非常熟悉才好,不然的话,使用fdisk来分区的话也只是--“雾里看花,水中望月”,掌握原理才是最重要的,而使用命令工具只是为了实现我们的需求,同时也可以加深我们对原理的理解。
(3)通知Linux内核分区信息的更改
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[root@xpleaf ~]# partprobe /dev/sdb |
分区完成后,需要此步骤,否则去使用这些分区时会出现错误信息。当然,如果不这样做的话,也可以采取重新启动系统的方法。
(4)格式化分区
格式化分区是为了创建文件系统,分配Inode和Block
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[root@xpleaf ~]# mkfs.ext4 /dev/sdb sdb sdb1 sdb2 sdb5 sdb6 [root@xpleaf ~]# mkfs.ext4 /dev/sdb1 …… This filesystem will be automaticallychecked every 31 mounts or
180 days, whichever comes first. Use tune2fs -c or -i to override .
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最后面提示说系统会定时检查文件系统,这里不想系统检查,则可以使用下面的命令:
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[root@xpleaf ~]# tune2fs -c - 1 /dev/sdb1
tune2fs 1.41 . 12 ( 17 -May- 2010 )
Setting maximal mount count to - 1
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(5)挂载分区
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[root@xpleaf ~]# mount /dev/sdb1 /mnt [root@xpleaf ~]# df -h Filesystem Size Used Avail Use% Mounted on /dev/sda3 9 .2G 1 .8G 7 .0G 21 % /
tmpfs 937M 0 937M 0 % /dev/shm
/dev/sda1 194M 34M 151M 19 % /boot
/dev/sdb1 107M 5 .6M 96M 6 % /mnt
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这里的挂载是临时挂载的,如果需要永久挂载(即开机挂载),则需要修改/etc/fstab文件,这里就不提及了。
OK,通过上面的实战步骤,实际上已经可以掌握fdisk的用法了,这样的话以后需要添加硬盘、分区格式化的话,就不会不知道怎么做了吧?
3.拓展:fdisk如何非交互分区???
从上面的fdisk分区过程可以看到,fidisk使用的是交互式的过程,如果学过parted命令,应该知道parted是可以进行非交互式的分区的,那么这里的问题是,fdisk可以非交互式分区吗?
答案是肯定可以的,请参考下面:
(1)将你要在fdisk命令行输入的命令实现写入一个文本文件,比如叫做fdisk.txt
(2)然后fdisk.txt的内容类似于这样:
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n p 1 0 100M w |
实际就是我们在交互式时的分区过程(当然这里与我上面的分区并非一样)
(3)然后用类似如下命令实现自动分区:
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fdisk /dev/hda < fdiskcmd.txt |
OK!内容就这么多了,看是没有用,重在实践,希望可以帮到大家!