Centos7扩展存储空间

1.在关机状态下，在Vm里面设置系统大小到需要的数值 ；

2.使用root权限登陆linux，df -h查看系统情况；

[root@cratedb-hk-01 ~]# df -h
文件系统                 容量  已用  可用 已用% 挂载点
/dev/mapper/centos-root   50G  1.5G   49G    3% /
devtmpfs                 3.8G     0  3.8G    0% /dev
tmpfs                    3.2G     0  3.2G    0% /dev/shm
tmpfs                    3.2G  9.1M  3.2G    1% /run
tmpfs                    3.2G     0  3.2G    0% /sys/fs/cgroup
/dev/xvda1              1014M  185M  830M   19% /boot
/dev/mapper/centos-home   46G   33M   46G    1% /home
tmpfs                    649M     0  649M    0% /run/user/0

　　fdisk -l

[root@cratedb-hk-01 ~]# fdisk -l

磁盘 /dev/xvda：214.7 GB, 214748364800 字节，419430400 个扇区
Units = 扇区 of 1 * 512 = 512 bytes
扇区大小(逻辑/物理)：512 字节 / 512 字节
I/O 大小(最小/最佳)：512 字节 / 512 字节
磁盘标签类型：dos
磁盘标识符：0x0009e984

    设备 Boot      Start         End      Blocks   Id  System
/dev/xvda1   *        2048     2099199     1048576   83  Linux
/dev/xvda2         2099200   209715199   103808000   8e  Linux LVM

3.没有找到挂载点，默认是/dev/sda或/dev/xvda必须要先试用fdisk格式化，初始化挂载磁盘才可以使用

[root@cratedb-hk-01 ~]# fdisk /dev/xvda
欢迎使用 fdisk (util-linux 2.23.2)。

更改将停留在内存中，直到您决定将更改写入磁盘。
使用写入命令前请三思。


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)

命令(输入 m 获取帮助)：p

磁盘 /dev/xvda：214.7 GB, 214748364800 字节，419430400 个扇区
Units = 扇区 of 1 * 512 = 512 bytes
扇区大小(逻辑/物理)：512 字节 / 512 字节
I/O 大小(最小/最佳)：512 字节 / 512 字节
磁盘标签类型：dos
磁盘标识符：0x0009e984

    设备 Boot      Start         End      Blocks   Id  System
/dev/xvda1   *        2048     2099199     1048576   83  Linux
/dev/xvda2         2099200   209715199   103808000   8e  Linux LVM

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)

命令(输入 m 获取帮助)：n
Partition type:
   p   primary (2 primary, 0 extended, 2 free)
   e   extended
Select (default p): p
分区号 (3,4，默认 3)：3
起始 扇区 (209715200-419430399，默认为 209715200)：
将使用默认值 209715200
Last 扇区, +扇区 or +size{K,M,G} (209715200-419430399，默认为 419430399)：
将使用默认值 419430399
分区 3 已设置为 Linux 类型，大小设为 100 GiB

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)

命令(输入 m 获取帮助)：t
分区号 (1-3，默认 3)：3
Hex 代码(输入 L 列出所有代码)：8e
已将分区“Linux”的类型更改为“Linux LVM”

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)

命令(输入 m 获取帮助)：w
The partition table has been altered!

Calling ioctl() to re-read partition table.

WARNING: Re-reading the partition table failed with error 16: 设备或资源忙.
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)
正在同步磁盘。

4：重启服务器

　　reboot

[root@cratedb-hk-01 ~]# fdisk -l

磁盘 /dev/xvda：214.7 GB, 214748364800 字节，419430400 个扇区
Units = 扇区 of 1 * 512 = 512 bytes
扇区大小(逻辑/物理)：512 字节 / 512 字节
I/O 大小(最小/最佳)：512 字节 / 512 字节
磁盘标签类型：dos
磁盘标识符：0x0009e984

    设备 Boot      Start         End      Blocks   Id  System
/dev/xvda1   *        2048     2099199     1048576   83  Linux
/dev/xvda2         2099200   209715199   103808000   8e  Linux LVM
/dev/xvda3       209715200   419430399   104857600   8e  Linux LVM

5：格式化分区，mkfs.ext3 /dev/xvda3一直挂载的分区是xvda3；

[root@cratedb-hk-01 ~]# mkfs.ext3 /dev/xvda3
mke2fs 1.42.9 (28-Dec-2013)
文件系统标签=
OS type: Linux
块大小=4096 (log=2)
分块大小=4096 (log=2)
Stride=0 blocks, Stripe width=0 blocks
6553600 inodes, 26214400 blocks
1310720 blocks (5.00%) reserved for the super user
第一个数据块=0
Maximum filesystem blocks=4294967296
800 block groups
32768 blocks per group, 32768 fragments per group
8192 inodes per group
Superblock backups stored on blocks: 
        32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208, 
        4096000, 7962624, 11239424, 20480000, 23887872

Allocating group tables: 完成                            
正在写入inode表: 完成                            
Creating journal (32768 blocks): 完成
Writing superblocks and filesystem accounting information: 完成   

6：输入以下指令：

[root@cratedb-hk-01 ~]# lvm
lvm> pvcreate /dev/xvda3
WARNING: ext3 signature detected on /dev/xvda3 at offset 1080. Wipe it? [y/n]: y
  Wiping ext3 signature on /dev/xvda3.
  Physical volume "/dev/xvda3" successfully created.
lvm> vgextend centos /dev/xvda3
  Volume group "centos" successfully extended
lvm> vgdisplay -v
  --- Volume group ---
  VG Name               centos
  System ID             
  Format                lvm2
  Metadata Areas        2
  Metadata Sequence No  5
  VG Access             read/write
  VG Status             resizable
  MAX LV                0
  Cur LV                3
  Open LV               3
  Max PV                0
  Cur PV                2
  Act PV                2
  VG Size               198.99 GiB
  PE Size               4.00 MiB
  Total PE              50942
  Alloc PE / Size       25342 / 98.99 GiB
  Free  PE / Size       25600 / 100.00 GiB
  VG UUID               Sa8iIa-EBdf-F0Zz-IJ3z-Xozx-L0Ob-ThRrNk
   
  --- Logical volume ---
  LV Path                /dev/centos/swap
  LV Name                swap
  VG Name                centos
  LV UUID                807WWG-hzhk-ichE-AEO2-HKaU-yCe4-rd8lob
  LV Write Access        read/write
  LV Creation host, time localhost, 2019-01-18 15:47:56 +0800
  LV Status              available
  # open                 2
  LV Size                <3.88 GiB
  Current LE             992
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     8192
  Block device           253:1
   
  --- Logical volume ---
  LV Path                /dev/centos/home
  LV Name                home
  VG Name                centos
  LV UUID                Lhl3gA-NKbL-8mod-hAiR-TE7G-9ZUC-PsfGG9
  LV Write Access        read/write
  LV Creation host, time localhost, 2019-01-18 15:47:56 +0800
  LV Status              available
  # open                 1
  LV Size                <45.12 GiB
  Current LE             11550
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     8192
  Block device           253:2
   
  --- Logical volume ---
  LV Path                /dev/centos/root
  LV Name                root
  VG Name                centos
  LV UUID                fOFhxK-gwNY-zuht-W64P-dQ5H-hTUJ-qXTSRk
  LV Write Access        read/write
  LV Creation host, time localhost, 2019-01-18 15:47:56 +0800
  LV Status              available
  # open                 1
  LV Size                50.00 GiB
  Current LE             12800
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     8192
  Block device           253:0
   
  --- Physical volumes ---
  PV Name               /dev/xvda2     
  PV UUID               ZItt1Y-FCC3-IxP9-Pw7C-0aJi-Yee4-WG3005
  PV Status             allocatable
  Total PE / Free PE    25343 / 1
   
  PV Name               /dev/xvda3     
  PV UUID               i3nEKb-grlP-cY7S-ayUf-WErf-d0dn-PMLRv3
  PV Status             allocatable
  Total PE / Free PE    25599 / 25599
   
lvm> lvextend -l +25599 /dev/mapper/centos-root
  Size of logical volume centos/root changed from 50.00 GiB (12800 extents) to <150.00 GiB (38399 extents).
  Logical volume centos/root successfully resized.
lvm> pvdisplay
  --- Physical volume ---
  PV Name               /dev/xvda2
  VG Name               centos
  PV Size               <99.00 GiB / not usable 3.00 MiB
  Allocatable           yes (but full)
  PE Size               4.00 MiB
  Total PE              25343
  Free PE               0
  Allocated PE          25343
  PV UUID               ZItt1Y-FCC3-IxP9-Pw7C-0aJi-Yee4-WG3005
   
  --- Physical volume ---
  PV Name               /dev/xvda3
  VG Name               centos
  PV Size               100.00 GiB / not usable 4.00 MiB
  Allocatable           yes 
  PE Size               4.00 MiB
  Total PE              25599
  Free PE               1
  Allocated PE          25598
  PV UUID               i3nEKb-grlP-cY7S-ayUf-WErf-d0dn-PMLRv3
   
lvm> quit
  Exiting.

7：扩展容量：

[root@cratedb-hk-01 ~]# xfs_growfs /dev/mapper/centos-root
meta-data=/dev/mapper/centos-root isize=512    agcount=4, agsize=3276800 blks
         =                       sectsz=512   attr=2, projid32bit=1
         =                       crc=1        finobt=0 spinodes=0
data     =                       bsize=4096   blocks=13107200, imaxpct=25
         =                       sunit=0      swidth=0 blks
naming   =version 2              bsize=4096   ascii-ci=0 ftype=1
log      =internal               bsize=4096   blocks=6400, version=2
         =                       sectsz=512   sunit=0 blks, lazy-count=1
realtime =none                   extsz=4096   blocks=0, rtextents=0
data blocks changed from 13107200 to 39320576

8：使用df -h查看

[root@cratedb-hk-01 ~]# df -h
文件系统                 容量  已用  可用 已用% 挂载点
/dev/mapper/centos-root  150G  1.5G  149G    1% /
devtmpfs                 3.8G     0  3.8G    0% /dev
tmpfs                    2.4G     0  2.4G    0% /dev/shm
tmpfs                    2.4G  9.0M  2.4G    1% /run
tmpfs                    2.4G     0  2.4G    0% /sys/fs/cgroup
/dev/xvda1              1014M  185M  830M   19% /boot
/dev/mapper/centos-home   46G   33M   46G    1% /home
tmpfs                    484M     0  484M    0% /run/user/0
[root@cratedb-hk-01 ~]# 

感谢：

https://www.cnblogs.com/panghaohan/p/6477517.html