Lunix reallocates root and home space memory

View virtual machine disk distribution

[root@data ~]# df -lh

 file system                   Capacity    Already used    You can use   Already used %  Mount point 
devtmpfs                 4.7G     0  4.7G    0% /dev
tmpfs                    4.7G     0  4.7G    0% /dev/shm
tmpfs                    4.7G   13M  4.7G    1% /run
tmpfs                    4.7G     0  4.7G    0% /sys/fs/cgroup
/dev/mapper/centos-root   50G   44G  6.3G   88% /
/dev/mapper/centos-home   46G   33M   46G    1% /home
/dev/sda1               1014M  149M  866M   15% /boot
tmpfs                    959M     0  959M    0% /run/user/0
overlay                   50G   44G  6.3G   88% /var/lib/docker/overlay2/25621b52617632efeb043f119ed67c0a0b6c8328d7835d11fa74395d0090866d/merged
overlay                   50G   44G  6.3G   88% /var/lib/docker/overlay2/4b60531fff0d2eb5abb3569ea4cd03c480b0562071782477a0da0f5bec14062c/merged
overlay                   50G   44G  6.3G   88% /var/lib/docker/overlay2/00e04c30d59668fa38acee4cde5ffb17ba4783bc2a43901750199b5d6de309f9/merged

Backup home Partition all files

[root@singlelucky ~]# tar cvf /tmp/home.tar /home

-- uninstall /home, If you can't uninstall , Terminate use first /home File system process --
-- It is best to restart the virtual machine , Make the virtual machine in the initial state --
> /home/
> /home/zhaozuozuo/
> /home/zhaozuozuo/.bash_logout
> /home/zhaozuozuo/.bash_profile
> /home/zhaozuozuo/.bashrc
> ;

uninstall home Partition

[root@singlelucky ~]# yum install psmisc

 Loaded plug-in ：fastestmirror
Determining fastest mirrors
 * base: mirrors.njupt.edu.cn
 * extras: mirrors.njupt.edu.cn
 * updates: mirrors.njupt.edu.cn
base                                                                                                       | 3.6 kB  00:00:00     
docker-ce-stable                                                                                           | 3.5 kB  00:00:00     
extras                                                                                                     | 2.9 kB  00:00:00     
updates                                                                                                    | 2.9 kB  00:00:00     
(1/2): docker-ce-stable/7/x86_64/primary_db                                                                |  63 kB  00:00:00     
(2/2): updates/7/x86_64/primary_db                                                                         | 9.6 MB  00:00:02     
 Resolving dependencies 
-->  Checking transactions 
--->  software package  psmisc.x86_64.0.22.20-17.el7  Will be   install 
-->  Resolve dependency complete 

 Dependency resolution 

==================================================================================================================================
 Package                       framework                           edition                                    Source                            size 
==================================================================================================================================
 Installing :
 psmisc                       x86_64                       22.20-17.el7                          base                       141 k

 Business summary 
==================================================================================================================================
 install   1  software package 

 Total Downloads ：141 k
 Installation size ：475 k
Is this ok [y/d/N]: y
Downloading packages:
psmisc-22.20-17.el7.x86_64.rpm                                                                             | 141 kB  00:00:00     
Running transaction check
Running transaction test
Transaction test succeeded
Running transaction
   Installing     : psmisc-22.20-17.el7.x86_64                                                                                    1/1 
   Verification in progress       : psmisc-22.20-17.el7.x86_64                                                                                    1/1 

 already installed :
  psmisc.x86_64 0:22.20-17.el7                                                                                                    

 complete ！

[root@singlelucky ~]# fuser -km /home/
[root@singlelucky ~]# umount /home

Delete /home Where lv

[root@singlelucky ~]# lvremove /dev/mapper/centos-home
Do you really want to remove active logical volume centos/home? [y/n]: （ Input ）y
Logical volume "home" successfully removed

Add disk space of the specified size to the specified partition

-- What I'm specifying here is root increase 40G, because home Only account file , Do not store other documents 
[root@singlelucky ~]# lvextend -L +40G /dev/mapper/centos-root
  
  Size of logical volume centos/root changed from 50.00 GiB (12800 extents) to 90.00 GiB (23040 extents).
  Logical volume centos/root successfully resized.

Expand /root file system

[root@singlelucky ~]# 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 23592960

The reconstruction home Partition

[root@singlelucky ~]# lvcreate -L 2G -n /dev/mapper/centos-home

 Logical volume "home" created.

Create file system

[root@singlelucky ~]# mkfs.xfs /dev/mapper/centos-home

meta-data=/dev/mapper/centos-home isize=512    agcount=4, agsize=131072 blks
         =                       sectsz=512   attr=2, projid32bit=1
         =                       crc=1        finobt=0, sparse=0
data     =                       bsize=4096   blocks=524288, 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

mount home

[root@singlelucky ~]# mount /dev/mapper/centos-home

home Backup file recovery

[root@singlelucky ~]# tar xvf /tmp/home.tar -C/

home/
home/wxl/
home/wxl/.bash_logout
home/wxl/.bash_profile
home/wxl/.bashrc

Check the new disk space distribution

[root@singlelucky ~]# df -lh

 file system                   Capacity    Already used    You can use   Already used %  Mount point 
devtmpfs                 4.7G     0  4.7G    0% /dev
tmpfs                    4.7G     0  4.7G    0% /dev/shm
tmpfs                    4.7G   13M  4.7G    1% /run
tmpfs                    4.7G     0  4.7G    0% /sys/fs/cgroup
/dev/mapper/centos-root   90G   44G   47G   49% /
/dev/sda1               1014M  149M  866M   15% /boot
tmpfs                    959M     0  959M    0% /run/user/0
/dev/mapper/centos-home 2G   33M  2G    2% /home