Centos ext4 format / directory space is insufficient and you need to allocate home space to the / directory
Note: You must log in as the root user at first. It will not work if you switch to root later.
1. View the file system
df -hT
lsblk
2. Back up data
cp -r /home homebak
3. Unmount the partition to be operated
Before uninstalling /home, you must first terminate all processes using the /home file system.
You can use fuser -m /home to check which process information, then kill -9 pid and then uninstall: umount /home. If you accidentally run fuser in the home directory -km /home, then use the forced uninstall command umount -l /home to uninstall.
4. Compress the volume home and compress the space to 1G
resize2fs -p /dev/mapper/VolGroup-lv_host 1G
If you encounter a prompt that you need to execute another command first, follow the prompts.
e2fsck -f /dev/mapper/VolGroup-lv_host
5. Remount and check the compression situation. You can see that the space in the home directory has been compressed.
Mount /dev/VolGroup/lv_host /home
Df -h
6. Reduce the logical partition of /dev/mapper/VolGroup-lv_host to the specified size. Here we reduce it to 2G.
lvreduce -L 2G /dev/mapper/VolGroup-lv_hose
7. Check the size of the physical volume. Free PE/Size is the available space.
vgdisplay
8. Increase the size of /dev/mapper'/VolGroup-lv_root (the increased value cannot be equal to the value of Free PE/Size in the above figure, Free PE/Size needs to leave some space)
lvextend -L +11G /dev/mapper/VolGroup-lv_root
9. Check if completed
10. Recover data
cp -r homebak/* /home/
