Hello, friend!
According to the command output, the problem may be caused by disk damage. You can use the following steps to solve the issue.
1. After the system enters the maintenance mode, the system automatically logs in as the root user.
2. Run the following command to detach the disk:
umount Disk name
3. If the following information is displayed, run the following commands to stop the running processes, and then unmount the disk again:
[root@EulerOS-BaseTemplate ~]# umount /dev/mapper/oss_vg-optlog_vol
umount: /opt: target is busy.
(In some cases useful info about processes that use
the device is found by lsof(8) or fuser(1))
fuser -ck /opt
umount Disk name
4. Run the following command to repair the disk:
fsck.ext4 -f -y Disk name
5. Run the following command to restart the VM:
reboot
6. Use PuTTY to log in to the faulty node as the sopuser user.
7. Run the following command to switch to the root user:
sudo su root
8. Run the following command to check whether the fault is rectified:
df -h
Check whether /dev/mapper/oss_vg-opt_vol and /dev/mapper/oss_vg-optlog_vol are displayed in the command output and whether data is displayed. The following is an example of the command output:

Hope this helps!