前言

由于最近在给公司管培生做培训，需要用到Docker，原以为20个G的CentOS够用了，但是发现还是小瞧了docker的镜像，安装到一半突然告知磁盘不够，所以马上开始紧急扩容

0x1 增加虚拟磁盘容量

虚拟机正常关机后，打开此虚拟机的设置，选择硬盘

然后在磁盘大小处填写需要扩展到合适的硬盘大小量，点击应用即可

然后打开虚拟机，可以看到磁盘已经有120个G了，但是根目录只有18个G

0x2 使用fdisk 扩容

在/dev/sda 这块磁盘中，可以看到当前挂载到根目录的为/dev/sda3，其他的则为系统所需磁盘 如果需要将磁盘扩展到挂载根目录的需要将/dev/sda3 删除，然后再重新分区

[root@localhost aaron]# fdisk /dev/sda
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.


Command (m for help): p

Disk /dev/sda: 128.8 GB, 128849018880 bytes, 251658240 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: 0x000ab441

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *        2048      616447      307200   83  Linux
/dev/sda2          616448     4810751     2097152   82  Linux swap / Solaris
/dev/sda3         4810752    41943039    18566144   83  Linux

Command (m for help): d
Partition number (1-3, default 3): 3
Partition 3 is deleted

Command (m for help): n
Partition type:
   p   primary (2 primary, 0 extended, 2 free)
   e   extended
Select (default p): p
Partition number (3,4, default 3):
First sector (4810752-251658239, default 4810752):
Using default value 4810752
Last sector, +sectors or +size{K,M,G} (4810752-251658239, default 251658239):
Using default value 251658239
Partition 3 of type Linux and of size 117.7 GiB is set

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

Calling ioctl() to re-read partition table.

WARNING: Re-reading the partition table failed with error 16: Device or resource busy.
The kernel still uses the old table. The new table will be used at
the next reboot or after you run partprobe(8) or kpartx(8)
Syncing disks.

上述步骤执行完之后，执行lsblk，可以看到当前更改还未生效

[root@localhost Desktop]# lsblk
NAME   MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT
sda      8:0    0  120G  0 disk
├─sda1   8:1    0  300M  0 part /boot
├─sda2   8:2    0    2G  0 part [SWAP]
└─sda3   8:3    0 17.7G  0 part /
sr0     11:0    1 1024M  0 rom

需要重启

reboot

重启之后执行lsblk ，可以看到此时/dev/sda3 分区的大小已经修改为117.7G了，但是我们使用df -hT查看却还是18G

下一步则需要刷新磁盘

xfs_growfs /dev/sda3

至此，磁盘扩容完毕

Ubuntu 使用xfs_growfs 无法成功

通知系统内核分区表的变化，输入：partprobe /dev/sda

对文件系统进行扩容，输入：resize2fs /dev/sda1

查看/dev/sda1是否扩容成功，输入：df -TH