对VM挂载新加入的磁盘

在虚拟机配置中增加磁盘后，启动Linux，使用root登录。

首先查看未分区的磁盘,使用下面命令：

## 查看未使用的磁盘
fdisk -l

磁盘/dev/sdb后面没有任何分区，是新挂载的磁盘

输入下面命令来开始对磁盘/dev/sdb进行分区

## 开始格式化磁盘 ##
fdisk /dev/sdb

有如下提示：

[root@localhost dev]# fdisk /dev/sdb
Welcome to fdisk (util-linux 2.23.).

Changes will remain in memory only, until you decide to write them.
Be careful before using the write command.

Command (m for help):

输入m来查看帮助，各选项功能如下：

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)

首选使用n来创建一个扩展分区，输入选项n：

Command (m for help): n
Partition type:
   p   primary ( primary,  extended,  free)
   e   extended
Select (default p): 

选择创建扩展分区，输入选项e，然后选择扩展分区编号、起始位置和大小，我们选择整个磁盘只创建一个扩展分区:

Select (default p): e
Partition number (-, default ):
First sector (-, default ):
Using default value
Last sector, +sectors or +size{K,M,G} (-, default ):
Using default value
Partition  of type Extended and of size  GiB is set

扩展分区创建好后，可以在此基础上进行创建逻辑分区，我们创建2个逻辑分区并分别设置为10G:

Command (m for help): n
Partition type:
   p   primary ( primary,  extended,  free)
   l   logical (numbered from )
Select (default p): l
Adding logical partition
First sector (-, default ):
Using default value
Last sector, +sectors or +size{K,M,G} (-, default ): +10G
Partition  of type Linux and of size  GiB is set

Command (m for help): n
Partition type:
   p   primary ( primary,  extended,  free)
   l   logical (numbered from )
Select (default p): l
Adding logical partition
First sector (-, default ):
Using default value
Last sector, +sectors or +size{K,M,G} (-, default ):
Using default value
Partition  of type Linux and of size  GiB is set

最后使用选项p来查看分好的分区：

Command (m for help): p

Disk /dev/sdb: 21.5 GB,  bytes,  sectors
Units = sectors of  *  =  bytes
Sector size (logical/physical):  bytes /  bytes
I/O size (minimum/optimal):  bytes /  bytes
Disk label type: dos
Disk identifier: 0x40e44e64

   Device Boot      Start         End      Blocks   Id  System
/dev/sdb1                          Extended
/dev/sdb5                         Linux
/dev/sdb6                     Linux

为磁盘分配好分区后，需要使用选项w来进行保存：

Command (m for help): w
The partition table has been altered!

Calling ioctl() to re-read partition table.
Syncing disks.

在执行partprobe命令来重新读取分区信息，如果有警告可以忽略。

## 重新读取分区信息 ##
partprobe

然后需要对磁盘进行格式化，使用mkfs将磁盘格式化为ext4格式(注意扩展分区不能进行格式化)

mkfs -t ext4 /dev/sdb5

mke2fs 1.42. (-Dec-)
Filesystem label=
OS type: Linux
Block size= (log=)
Fragment size= (log=)
Stride= blocks, Stripe width= blocks
 inodes,  blocks
 blocks (5.00%) reserved for the super user
First data block=
Maximum filesystem blocks=
 block groups
 blocks per group,  fragments per group
 inodes per group
Superblock backups stored on blocks:
    , , , , , , , 

Allocating group tables: done
Writing inode tables: done
Creating journal ( blocks): done
Writing superblocks and filesystem accounting information: done

然后我们创建两个目录来挂载这两个逻辑分区：

## 然后创建目录 ##
mkdir /disk5 /disk6

## 使用mount命令来挂载目录 ##
mount /dev/sdb5 /disk5
mount /dev/sdb6 /disk6

最后使用mount命令来查看挂载情况

[root@localhost dev]# ## 使用mount命令来查看挂载情况 ##
[root@localhost dev]# mount | grep "sdb"
/dev/sdb5 on /disk5 type ext4 (rw,relatime,seclabel,data=ordered)
/dev/sdb6 on /disk6 type ext4 (rw,relatime,seclabel,data=ordered)