Linux磁盘扩容（添加挂载点）

末蓝、 2023-02-10 15:27 101阅读 0赞

**目录**

一、添加新磁盘

二、查看新挂载点

三、为挂载点创建分区

四、格式化分区

五、分区添加挂载点

六、更换目录挂载点

--------------------

### 一、添加新磁盘 ###

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxMjYyNTkzNDIx_size_16_color_FFFFFF_t_70][]![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxMjYyNTkzNDIx_size_16_color_FFFFFF_t_70 1][]

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxMjYyNTkzNDIx_size_16_color_FFFFFF_t_70 2][]![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxMjYyNTkzNDIx_size_16_color_FFFFFF_t_70 3][]

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxMjYyNTkzNDIx_size_16_color_FFFFFF_t_70 4][]![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxMjYyNTkzNDIx_size_16_color_FFFFFF_t_70 5][]

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxMjYyNTkzNDIx_size_16_color_FFFFFF_t_70 6][]

### 二、查看新挂载点 ###

查看已挂载点

df -h

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxMjYyNTkzNDIx_size_16_color_FFFFFF_t_70 7][]

查看所有挂载点

fdisk -l

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxMjYyNTkzNDIx_size_16_color_FFFFFF_t_70 8][]

### 三、为挂载点创建分区 ###

fdisk /dev/sdb
    m

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxMjYyNTkzNDIx_size_16_color_FFFFFF_t_70 9][]

> 命令(输入 m 获取帮助)：m  
> 命令操作  
> 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)

打印分区表

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxMjYyNTkzNDIx_size_16_color_FFFFFF_t_70 10][]

创建新分区

![2020052109444048.png][]

p 表示主分区，e 表示扩展分区 ，一个物理磁盘的主分区至少1个最多4个，扩展分区最少0个最多1个

主分区相当于windows系统的活动磁盘，系统内核和开机程序必须放在主分区

扩展分区相当于windowns系统的非活动分区，扩展分区通常用于存放文件和安装非系统依赖程序

![20200521095438721.png][]

三个回车键

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxMjYyNTkzNDIx_size_16_color_FFFFFF_t_70 11][]

再次打印分区表

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxMjYyNTkzNDIx_size_16_color_FFFFFF_t_70 12][]

w 保存分区

### 四、格式化分区 ###

查看分区，此时新分区还没被使用，和windows系统一样，需要格式化分区之后才能使用磁盘（新分区）

df -h

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxMjYyNTkzNDIx_size_16_color_FFFFFF_t_70 13][]

再次查看所有可用分区

fdisk -l

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxMjYyNTkzNDIx_size_16_color_FFFFFF_t_70 14][] 四个物理磁盘

> 磁盘 /dev/sda：42.9 GB  
> 磁盘 /dev/sdb：644.2 GB  
> 磁盘 /dev/mapper/centos-root：37.6 GB  
> 磁盘 /dev/mapper/centos-swap：4294 MB

> /dev/sda 磁盘分区： /dev/sda1 /dev/sda2  
> /dev/sdb 磁盘分区：/dev/sdb

格式化分区

注意：格式化的是分区符，不是物理磁盘

mkfs.ext4 /dev/sdb1

发现不能格式化分区，原因是这个单独的物理磁盘分区只有一个逻辑分区

![2020052110123633.png][]

# 进入/dev/sdb磁盘
    fdisk /dev/sdb
    # 打印分区
    p

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxMjYyNTkzNDIx_size_16_color_FFFFFF_t_70 15][]

# 删除分区
    d
    # 打印分区
    p

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxMjYyNTkzNDIx_size_16_color_FFFFFF_t_70 16][]

# 创建新分区
    n
    # 使用主分区
    p
    # 再敲三个回车确认

# 再次查看新分区
    fdisk -l

![20200521102417198.png][]

重新格式化 /dev/sdb1/ 分区

mkfs.ext4 /dev/sdb1

格式化成功

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxMjYyNTkzNDIx_size_16_color_FFFFFF_t_70 17][]

### 五、分区添加挂载点 ###

# 创建新目录
    mkdir /data
    # 给/data目录添加挂载点/dev/sdb1
    mount /dev/sdb1 /data
    # 查看已挂载点
    df -h

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxMjYyNTkzNDIx_size_16_color_FFFFFF_t_70 18][]

查看现有分区情况

cat /etc/fstab

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxMjYyNTkzNDIx_size_16_color_FFFFFF_t_70 19][]

将新增挂载信息写入 /etc/fstab 文件，使其永久生效

echo "/dev/sdb1 /data ext4 defaults 0 0" >> /etc/fstab

重新查看

cat /etc/fstab
    df -h

lsblk命令查看

lsblk

### 六、更换目录挂载点 ###

如果只是单个目录挂载的空间不够，其他挂载点容量充足的情况下可以不添加分区

解决办法：

1.使用软连接：直接将目录连接到挂载点大的目录下

2.重新挂载目录：卸载挂载点，然后重新将挂载点挂到所需目录（推荐）

> 比如软件都放在/opt 目录下，但是该目录没有挂载，只在/目录挂载了50G的硬盘  
> /data 目录挂载了1T的数据，但是基本没用上，此时可以先把 /data目录的磁盘卸载了  
> 然后再把之前挂载在 /data目录下的磁盘挂载到 /opt 目录下，重新修改/etc/fstab文件

卸载挂载点命令：umount 挂载命令：mount 查看挂载点：lsblk 或 df -h

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