思路
基本的思路是第一步通过界面给虚拟机扩展磁盘，第二步登录OS7并为扩展的磁盘创建分区，第三步格式化或者转换分区的格式类型，第四步将指定文件目录挂载到新建分区中，第五步设置开机自启完成挂载，第六步将原先磁盘的文件移动到新分区中，并创建软连接，保留原始的使用路径。
虚拟机扩充磁盘
提示：我们用vmware作为虚拟化，我们可以使用vmware的操作界面为虚拟机扩展磁盘，但是需要注意如果虚拟机有备份需要删掉，否则无法完成扩展。
创建分区
提示：使用fdisk /dev/sda 命令创建分区，我们可以输入 m 查看详细使用，内置有创建，删除分区等操作
> sudo 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):
Command (m for help): p
Disk /dev/sda: 32.2 GB, 32212254720 bytes, 62914560 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: 0x00038019
Device Boot Start End Blocks Id System
/dev/sda1 * 2048 2099199 1048576 83 Linux
/dev/sda2 2099200 41943039 19921920 8e Linux LVM
Command (m for help): n
Partition type:
p primary (2 primary, 0 extended, 2 free)
e extended
Select (default p):
Using default response p
Partition number (3,4, default 3):
First sector (41943040-62914559, default 41943040):
Using default value 41943040
Last sector, +sectors or +size{K,M,G} (41943040-62914559, default 62914559):
Using default value 62914559
Partition 3 of type Linux and of size 10 GiB is set
Command (m for help):
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.
> sudo partprobe
# 查看分区情况
> sudo fdisk -l
Disk /dev/sda: 32.2 GB, 32212254720 bytes, 62914560 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: 0x00038019
Device Boot Start End Blocks Id System
/dev/sda1 * 2048 2099199 1048576 83 Linux
/dev/sda2 2099200 41943039 19921920 8e Linux LVM
/dev/sda3 41943040 62914559 10485760 83 Linux
Disk /dev/mapper/centos-root: 18.2 GB, 18249416704 bytes, 35643392 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
格式化分区
提示：使用mkfs.xfs /dev/sda3进行格式分区，并将分区的磁盘格式修改成xfs。
> sudo mkfs.xfs /dev/sda3
meta-data=/dev/sda3 isize=512 agcount=4, agsize=655360 blks
= sectsz=512 attr=2, projid32bit=1
= crc=1 finobt=0, sparse=0
data = bsize=4096 blocks=2621440, imaxpct=25
= sunit=0 swidth=0 blks
naming =version 2 bsize=4096 ascii-ci=0 ftype=1
log =internal log bsize=4096 blocks=2560, version=2
= sectsz=512 sunit=0 blks, lazy-count=1
realtime =none extsz=4096 blocks=0, rtextents=0
挂载分区
提示：mount 源数据目录 挂载的目录。
> sudo mkdir /data
> sudo mount /dev/sda3 /data
> df -h
Filesystem Size Used Avail Use% Mounted on
devtmpfs 2.9G 0 2.9G 0% /dev
tmpfs 2.9G 0 2.9G 0% /dev/shm
tmpfs 2.9G 12M 2.9G 1% /run
tmpfs 2.9G 0 2.9G 0% /sys/fs/cgroup
/dev/mapper/centos-root 17G 8.6G 8.5G 51% /
/dev/sda1 1014M 153M 862M 16% /boot
cm_processes 2.9G 1.7M 2.9G 1% /run/cloudera-scm-agent/process
tmpfs 579M 0 579M 0% /run/user/1000
/dev/sda3 10G 33M 10G 1% /data
分区开机自启
提示：设置开启开机自动挂载分区，不用每次重启手动挂载
> sudo blkid /dev/sda3
/dev/sda3: UUID="a306328b-34c3-404e-9f76-f49e967ce333" TYPE="xfs"
> sudo vi /etc/fstab
#文件末尾追加即可开机自启
UUID=a306328b-34c3-404e-9f76-f49e967ce333 /data xfs defaults 0 0
将原先分区下的大文件移动到新挂载盘
提示：将数据大的文件迁到新的分区，并将迁移后的文件挂载到原来的访问路径下，这样我们可以以旧的方式访问文件。挂载其实可以理解windos系统创建快捷方式，源目录就是源文件，挂载目录则是快捷方式。
#切换到根目录
> sudo cd /
#查看当前目录中较大占用空间的文件夹
> sudo df -h
Filesystem Size Used Avail Use% Mounted on
devtmpfs 3.8G 0 3.8G 0% /dev
tmpfs 3.9G 0 3.9G 0% /dev/shm
tmpfs 3.9G 12M 3.8G 1% /run
tmpfs 3.9G 0 3.9G 0% /sys/fs/cgroup
/dev/mapper/centos-root 17G 7.8G 9.3G 46% /
/dev/sda1 1014M 153M 862M 16% /boot
cm_processes 3.9G 2.1M 3.9G 1% /run/cloudera-scm-agent/process
tmpfs 781M 0 781M 0% /run/user/1000
/dev/sda3 10G 6.7G 3.4G 67% /data
#切换到/目录下，寻找较大的文件
> sudo cd /
> sudo du -h --max-depth=1 ./
121M ./boot
0 ./dev
du: cannot access ‘./proc/18225/task/18225/fd/4’: No such file or directory
du: cannot access ‘./proc/18225/task/18225/fdinfo/4’: No such file or directory
du: cannot access ‘./proc/18225/fd/3’: No such file or directory
du: cannot access ‘./proc/18225/fdinfo/3’: No such file or directory
0 ./proc
14M ./run
0 ./sys
33M ./etc
30M ./root
du: cannot access ‘./var/lib/cloudera-host-monitor/ts/type/partition_metadata/000019.sst’: No such file or directory
3.3G ./var
11M ./tmp
1.9G ./usr
80K ./home
0 ./media
0 ./mnt
0 ./srv
1.6G ./yarn
314M ./dfs
6.7G ./data
5.4G ./opt
14G ./
#将./opt目录切换到新的分区中
> sudo mv /opt /data/opt
# 创建软连接
> sudo ln -s /data/opt /opt
> sudo cd /opt
total 0
drwxr-xr-x 6 cloudera-scm cloudera-scm 67 Oct 10 05:14 cloudera
drwxrwxr-x 2 daiyongjun daiyongjun 62 Sep 8 21:20 document
drwxrwxr-x 2 daiyongjun daiyongjun 150 Sep 8 21:11 package
drwxr-xr-x. 2 daiyongjun daiyongjun 6 Oct 30 2018 rh
drwxr-xr-x. 5 daiyongjun daiyongjun 94 Sep 8 21:14 software
> sudo df -h
Filesystem Size Used Avail Use% Mounted on
devtmpfs 2.9G 0 2.9G 0% /dev
tmpfs 2.9G 0 2.9G 0% /dev/shm
tmpfs 2.9G 12M 2.9G 1% /run
tmpfs 2.9G 0 2.9G 0% /sys/fs/cgroup
/dev/mapper/centos-root 17G 3.9G 14G 23% /
/dev/sda3 10G 5.4G 4.7G 54% /data
/dev/sda1 1014M 153M 862M 16% /boot
tmpfs 579M 0 579M 0% /run/user/1000
cm_processes 2.9G 1.7M 2.9G 1% /run/cloudera-scm-agent/process
