Centos系统根目录扩容磁盘

1，查看磁盘空间和分区

[root@ loaclhost ~]# df -hT

[root@ loaclhost ~]# fdisk -l

/dev/sdb/为新添加的硬盘

2，对新增加的磁盘进行分区

[root@ loaclhost ~]# 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 0x647d60f3.

Command (m for help): n
Partition type:
   p   primary (0 primary, 0 extended, 4 free)
   e   extended
Select (default p): p  
Partition number (1-4, default 1): 
First sector (2048-41943039, default 2048): 
Using default value 2048
Last sector, +sectors or +size{K,M,G} (2048-41943039, default 41943039): +20G
Using default value 41943039
Partition 1 of type Linux and of size 20 GiB is set

可以默认，可以输入相应的值。

3，创建物理卷

[root@ loaclhost ~]# pvcreate /dev/sdb1
  Physical volume "/dev/sdb1" successfully created.

4，查看物理卷信息

[root@ loaclhost ~]# pvdisplay

已经创建物理卷

[root@ loaclhost ~]# vgdisplay

这里还没有加入新添加的卷

5，将新分区/dev/sdb1加入到根目录分中

[root@ loaclhost ~]# vgextend centos /dev/sdb1
  Volume group "centos" successfully extended

6，查看新卷组信息

[root@ loaclhost ~]# vgdisplay

已经生成新的加的卷组信息了。

7，把VG中多余的空间添加到/dev/mapper/centos-root中，进行扩容

[root@ loaclhost ~]# lvextend -l +100%FREE /dev/mapper/centos-root /dev/sdb1
  Size of logical volume centos/root changed from 26.99 GiB (6910 extents) to <46.99 GiB (12029 extents).
  Logical volume centos/root successfully resized.

8，同步系统文件

[root@loaclhost ~]# xfs_growfs /dev/mapper/centos-root 

9，查看磁盘，验证是否成功

[root@ loaclhost ~]# df -hT

对比开始时，根目录下磁盘多了20G的空间。