The error message “Permission denied” is reported when I log in using VNC or SSH key.
The VNC login error is shown below:
The SSH login error is shown below:
Possible Reasons
Using the VNC or SSH login will call system-auth for authentication if this module is configured in the /etc/pam.d/login configuration file. By default, the system-auth module introduces the pam_limits.so module. The default system-auth configuration is as shown below:
The pam_limits.so module is mainly used to limit the use of system resources during the user session. Its default configuration file /etc/security/limits.conf specifies the maximum number of files, the maximum number of threads, the maximum memory and other resources that a user can use. See the table below for details.
Parameter
Description
soft nofile
The maximum number of open file descriptors (soft limit)
hard nofile
The maximum number of open file descriptors (hard limit), which cannot be exceeded.
fs.file-max
The maximum number of open file handles (struct file in the kernel) at the system level.
fs.nr_open
The maximum number of file descriptors (fd) assigned to a process
The login failure may be caused by incorrect configurations of the maximum number of open file descriptors for the root account in the /etc/security/limits.conf configuration file. The set value of soft nofile should be no more than hard nofile, and hard nofile should be no more than fs.nr_open.
Solutions
Perform the troubleshooting procedure to correct the relationship configurations of soft nofile, hard nofile and fs.nr_open.
