使用SSH第一次登录一台Linux机器时，较容易遇到如下错误：
Host key not found from database.
Key fingerprint:
xesob-decep-nuzuv-rolen-vymum-tefed-rivuf-bisol-rirer-divyz-nixux
You can get a public key's fingerprint by running
% ssh-keygen -F publickey.pub
on the keyfile.
warning: tcsetattr failed in ssh_rl_set_tty_modes_for_fd: fd 1: Interrupted system call
经常需要反复多次才能够SSH成功，实际上有办法绕过这个错误，做法在ssh命令前加strace，如：
strace -o t ssh root@192.168.0.52#1800
这样就能一次性能成功了。