Linux如何将未分配的硬盘挂载出来

情景说明

客户给了几台服务器，说500G硬盘，但到手操作的时候，使用命令查看，发现只有不到200的硬盘

[root@localhost ~]# df -h
Filesystem               Size  Used Avail Use% Mounted on
/dev/mapper/centos-root   50G  6.8G   44G  14% /
devtmpfs                  63G     0   63G   0% /dev
tmpfs                     63G   88K   63G   1% /dev/shm
tmpfs                     63G  272M   63G   1% /run
tmpfs                     63G     0   63G   0% /sys/fs/cgroup
/dev/mapper/centos-home   48G  6.7G   41G  15% /home
/dev/sda1                497M  158M  340M  32% /boot
tmpfs                     13G   24K   13G   1% /run/user/0

再使用fdisk查看，发现的确是500G硬盘，但挂载的只有100多

[root@localhost ~]# fdisk -l
Disk /dev/sda: 536.9 GB, 536870912000 bytes, 1048576000 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: 0x000a3e10
   Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *        2048     1026047      512000   83  Linux
/dev/sda2         1026048   209715199   104344576   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: 2147 MB, 2147483648 bytes, 4194304 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: 50.9 GB, 50944016384 bytes, 99500032 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

解决办法

询问了运维同事，给出了不关机新建分区的办法，如下：

（1）使用fdisk进入待分区的磁盘中（fdisk -l可以查看只有一块硬盘）：

fdisk /dev/sda

（2）新增一个主分区：p --> n --> 三次enter默认 --> p --> w

（3）刷新sda分区表：partprobe

（4）对刚分好分区的磁盘格式化：mkfs.ext3 /dev/sda3

（5）创建挂载点：mkdir /test

（6）查看UUID：blkid

（7）更改/etc/fstab文件，如：echo "/dev/sda3 /test ext3 defaults 1 1 " >> /etc/fstab

（8）挂载文件系统：mount -a

再次使用fdisk能看到多了一个分区

[root@localhost ~]# fdisk -l
Disk /dev/sda: 536.9 GB, 536870912000 bytes, 1048576000 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: 0x000a3e10
   Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *        2048     1026047      512000   83  Linux
/dev/sda2         1026048   209715199   104344576   8e  Linux LVM
/dev/sda3       209715200  1048575999   419430400   83  Linux