# 从 ~/.ssh/known_hosts 删除指定 hostname 的公钥指纹
-R hostname 
 

# 远程登录密钥权限
# https://docs.aws.amazon.com/zh_cn/emr/latest/ManagementGuide/emr-troubleshoot-error-permissions.html
chmod og-rwx mykey.pem
 

SSH 教程 - 服务器密钥变更