This topic describes how to troubleshoot and resolve the issue where the SSH service fails to start even though no error messages are displayed when you use the service or systemctl command to start it in a Linux instance environment.

Causes

This issue is usually caused by an abnormal configuration of the PATH environment variable or the removal of files related to the SSH package.

Procedure

Log in to the target instance. For operation details, refer to Logging in to Linux instances.

Execute the following command to check whether the environment variable configuration is specified as expected.

echo $PATH

Normally, information similar to the following is returned. This value is the default value of the PATH environment variable.

/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If other information (not the default value) is returned, the environment variable is altered from its default. Execute the following command to reset the environment variable.

export PATH=/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

Execute the following command to find and confirm the path of the SSHD program. Then, determine whether files related to the SSH software package are removed.

find / -name sshd

If the output shows information similar to the following, the default path of the SSHD program exists (the files exist). Skip the subsequent operations.

/usr/sbin/sshd

If no similar information is returned after you execute the find / -name sshd command, the files do not exist. Continue with the subsequent operations.

Execute the following command to reinstall the SSH package.

yum install -y openssh

Execute the following command to restart the SSH service.

systemctl restart sshd.service

Execute the following command to view the SSH service status.

systemctl status sshd.service

If the following output is displayed, the SSH service is running.

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