centos7 添加硬盘和分区

首先查看系统中的硬盘

[root@svnhost ~]# fdisk -l

Disk /dev/sda: 120.0 GB, 120034123776 bytes, 234441648 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: 0x00033922

   Device Boot      Start         End      Blocks   Id  System

/dev/sda1   *        2048     1026047      512000   83  Linux

/dev/sda2         1026048   234440703   116707328   8e  Linux LVM

Disk /dev/mapper/centos-root: 53.7 GB, 53687091200 bytes, 104857600 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 /dev/mapper/centos-swap: 12.0 GB, 12004098048 bytes, 23445504 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 /dev/sdb: 1999.8 GB, 1999844147200 bytes, 3905945600 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 /dev/mapper/centos-home: 53.8 GB, 53750005760 bytes, 104980480 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

系统中有2块盘/dev/sda和/dev/sdb. /dev/sda已经做好分区。下面对/dev/sdb做分区

 

[root@svnhost ~]# fdisk /dev/sdb

Welcome to fdisk (util-linux 2.23.2).

Changes will remain in memory only, until you decide to write them.

Be careful before using the write command.

Device does not contain a recognized partition table

Building a new DOS disklabel with disk identifier 0x8626c507.

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

   g   create a new empty GPT partition table

   G   create an IRIX (SGI) partition table

   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                                                 //新建主分区

Partition type:

   p   primary (0 primary, 0 extended, 4 free)

   e   extended

Select (default p):

Using default response p

Partition number (1-4, default 1):

First sector (2048-3905945599, default 2048):

Using default value 2048

Last sector, +sectors or +size{K,M,G} (2048-3905945599, default 3905945599): +500G                                 //输入分区大小

Partition 1 of type Linux and of size 500 GiB is set

Command (m for help): p                                                                                                                                    //打印分区

Disk /dev/sdb: 1999.8 GB, 1999844147200 bytes, 3905945600 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: 0x8626c507

   Device Boot      Start         End      Blocks   Id  System

/dev/sdb1            2048  1048578047   524288000   83  Linux

Command (m for help): n

Partition type:

   p   primary (1 primary, 0 extended, 3 free)

   e   extended

Select (default p):

Using default response p

Partition number (2-4, default 2):

First sector (1048578048-3905945599, default 1048578048):

Using default value 1048578048

Last sector, +sectors or +size{K,M,G} (1048578048-3905945599, default 3905945599): +500G

Partition 2 of type Linux and of size 500 GiB is set

Command (m for help): p

Disk /dev/sdb: 1999.8 GB, 1999844147200 bytes, 3905945600 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: 0x8626c507

   Device Boot      Start         End      Blocks   Id  System

/dev/sdb1            2048  1048578047   524288000   83  Linux

/dev/sdb2      1048578048  2097154047   524288000   83  Linux

Command (m for help): n                                                                                                                           //新建扩展分区

Partition type:

   p   primary (2 primary, 0 extended, 2 free)

   e   extended

Select (default p): e

Partition number (3,4, default 3):

First sector (2097154048-3905945599, default 2097154048):

Using default value 2097154048

Last sector, +sectors or +size{K,M,G} (2097154048-3905945599, default 3905945599):

Using default value 3905945599

Partition 3 of type Extended and of size 862.5 GiB is set

Command (m for help): p

Disk /dev/sdb: 1999.8 GB, 1999844147200 bytes, 3905945600 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: 0x8626c507

   Device Boot      Start         End      Blocks   Id  System

/dev/sdb1            2048  1048578047   524288000   83  Linux

/dev/sdb2      1048578048  2097154047   524288000   83  Linux

/dev/sdb3      2097154048  3905945599   904395776    5  Extended

Command (m for help): n                                                                                                               //新建逻辑分区

Partition type:

   p   primary (2 primary, 1 extended, 1 free)

   l   logical (numbered from 5)

Select (default p): l

Adding logical partition 5

First sector (2097156096-3905945599, default 2097156096):

Using default value 2097156096

Last sector, +sectors or +size{K,M,G} (2097156096-3905945599, default 3905945599):

Using default value 3905945599

Partition 5 of type Linux and of size 862.5 GiB is set

Command (m for help): p

Disk /dev/sdb: 1999.8 GB, 1999844147200 bytes, 3905945600 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: 0x8626c507

   Device Boot      Start         End      Blocks   Id  System

/dev/sdb1            2048  1048578047   524288000   83  Linux

/dev/sdb2      1048578048  2097154047   524288000   83  Linux

/dev/sdb3      2097154048  3905945599   904395776    5  Extended

/dev/sdb5      2097156096  3905945599   904394752   83  Linux

Command (m for help): w                                                                                        //写入新的分区表

The partition table has been altered!

Calling ioctl() to re-read partition table.

Syncing disks.

 

创建文件系统

[root@svnhost ~]# mkfs -t ext3 /dev/sdb1

[root@svnhost /]# mkfs -t ext3 /dev/sdb2

[root@svnhost /]# mkfs -t ext3 /dev/sdb5

 

编辑系统文件

[root@svnhost /]#vi /etc/fstab

添加：

/dev/sdb1                       /u01            ext3    defaults        0 0

/dev/sdb2                       /u02            ext3    defaults        0 0

/dev/sdb5                       /u03            ext3    defaults        0 0

 

至此，新建的硬盘分区在系统重启时就会自动挂载。

 

主分区，扩展分区和逻辑分区

 

主分区,也称为主磁盘分区,和扩展分区、逻辑分区一样,是一种分区类型。主分区中不能再划分其他类型的分区,因此每个主分区都相当于一个逻辑磁盘(在这一点上主分区和逻辑分区很相似,但主分区是直接在硬盘上划分的,逻辑分区则必须建立于扩展分区中)。

1. 一个硬盘可以有1到3个主分区和1个扩展分区,也可以只有主分区而没有扩展分区,但主分区必须至少有1个,扩展分区则最多只有1个,且主分区+扩展分区总共不能超过4个。逻辑分区可以有若干个。  

 

(硬盘的第一个扇区最重要，其上面有硬盘主引导记录（占用446bytes）和分区表（占用64 bytes），之所以只能有四个主分区就是因为分区表只有64B，只能装下4条记录)

所以只能有四个主分区的硬盘的限制，并不是操作系统的限制，而最多只能有一个拓展分区则是操作系统的限制

 

2. 分出主分区后,其余的部分可以分成扩展分区,一般是剩下的部分全部分成扩展分区,也可以不全分,剩下的部分就浪费了。  

3. 扩展分区不能直接使用,必须分成若干逻辑分区。所有的逻辑分区都是扩展分区的一部分。   硬盘的容量=主分区的容量+扩展分区的容量;   扩展分区的容量=各个逻辑分区的容量之和。  

4. 由主分区和逻辑分区构成的逻辑磁盘称为驱动器(Drive)或卷(Volume)。

5. 激活的主分区会成为“引导分区”(或称为“启动分区”),引导分区会被操作系统和主板认定为第一个逻辑磁盘(在DOS/Windows中会被识别为“驱动器C:”或“本地磁盘C:”,即通称的C盘)。有关DOS/Windows启动的重要文件,如引导记录、boot.ini、ntldr、ntdetect.com等,必须放在引导分区中。