Unix / Linux Remove (Delete) OpenSSH Server – nixCraft
https://www.cyberciti.biz/faq/howto-unix-linux-remove-delete-opensshd-server/
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linux – How do I troubleshoot when systemctl will not restart the sshd service? – Unix & Linux Stack Exchange
https://unix.stackexchange.com/questions/732688/how-do-i-troubleshoot-when-systemctl-will-not-restart-the-sshd-service
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https://library.gabia.com/contents/infrahosting/9008/