Adjust the size of home and root partitions under CentOS

Since we sometimes cannot predict or use the wrong drive letter partition, it often causes great inconvenience in our subsequent operations. Here I will record the wrong partition and then store the home and root partitions. The entire process of space resizing!
　
　①Check the partition status of our existing machine

Centos download:

[root@weidianserver2 ~]# df -h
Filesystem                             Size  Used Avail Use% Mounted on
/dev/mapper/vg_weidianserver2-lv_root   50G   44G  2.8G  95% /
tmpfs                                  7.8G   72K  7.8G   1% /dev/shm
/dev/sda1                              485M   39M  421M   9% /boot
/dev/mapper/vg_weidianserver2-lv_home  860G  4.4G  812G   1% /home

We can find the root partition and home Partitioning creates great irrationality, so here we will shrink the storage in the home partition and add the compressed storage to the root!
　
　②First uninstall our home partition and compress the size of our home partition

[root@weidianserver2 ~]#  umount /home
[root@weidianserver2 ~]# df -h
Filesystem                             Size  Used Avail Use% Mounted on
/dev/mapper/vg_weidianserver2-lv_root   50G   44G  2.8G  95% /
tmpfs                                  7.8G   72K  7.8G   1% /dev/shm
/dev/sda1                              485M   39M  421M   9% /boot
[root@weidianserver2 ~]# resize2fs -p /dev/mapper/vg_weidianserver2-lv_home 20G
resize2fs 1.41.12 (17-May-2010)
请先运行 'e2fsck -f /dev/mapper/vg_weidianserver2-lv_home'.
 
[root@weidianserver2 ~]# e2fsck -f /dev/mapper/vg_weidianserver2-lv_home
e2fsck 1.41.12 (17-May-2010)
第一步: 检查inode,块,和大小
第二步: 检查目录结构
第3步: 检查目录连接性
Pass 4: Checking reference counts
第5步: 检查簇概要信息
/dev/mapper/vg_weidianserver2-lv_home: 330/57229312 files (3.9% non-contiguous), 4737926/228899840 blocks
[root@weidianserver2 ~]# resize2fs -p /dev/mapper/vg_weidianserver2-lv_home 20G
resize2fs 1.41.12 (17-May-2010)
Resizing the filesystem on /dev/mapper/vg_weidianserver2-lv_home to 5242880 (4k) blocks.
Begin pass 2 (max = 33784)
正在重定位块            XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
Begin pass 3 (max = 6986)
正在扫描inode表          XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
Begin pass 4 (max = 147)
正在更新inode引用       XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
The filesystem on /dev/mapper/vg_weidianserver2-lv_home is now 5242880 blocks long.

③We can see from the running results that we have compressed our home to 20G, At this time we can reload our home directory

[root@weidianserver2 ~]# mount /home
[root@weidianserver2 ~]# df -h
Filesystem                             Size  Used Avail Use% Mounted on
/dev/mapper/vg_weidianserver2-lv_root   50G   44G  2.8G  95% /
tmpfs                                  7.8G   72K  7.8G   1% /dev/shm
/dev/sda1                              485M   39M  421M   9% /boot
/dev/mapper/vg_weidianserver2-lv_home   20G  4.4G   15G  24% /home

This completes the compression and reloading of home, as shown below:

④We have processed the home block in the above three steps, but our free hard disk has not been added to the root, so next we will add the compressed disk to the root:

[root@localhost ~]# lvextend -L +812G /dev/mapper/vg_weidianserver2-lv_root
注：lvextend -L +283G为在文件系统上增加283G
[root@localhost ~]# resize2fs -p /dev/mapper/vg_weidianserver2-lv_root

It takes a little time to reload and mount, but we can also continuously check the size of the drive letter during this time. At this time, we will find that the size of the root drive letter will be a little bit smaller. increase, as shown below:

From the final result of the above picture, we can see that we compressed the free drive letter in home into 812G and added it to root, so that we The root space has been increased instantly; finally, thank you for reading. If you have any questions, you can leave a message for discussion. Thank you!

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