Could not load host key: /etc/ssh/ssh_host_rsa_key /etc/ssh/ssh_host_dsa_key问题

Could not load host key: /etc/ssh/ssh_host_rsa_key

Could not load host key: /etc/ssh/ssh_host_dsa_key

问题的解决

症状：
用命令/usr/sbin/sshd启动sshd时出现：
系统提示“Could not load host key: /etc/ssh/ssh_host_key
Could not load host key: /etc/ssh/ssh_host_rsa_key
Could not load host key: /etc/ssh/ssh_host_dsa_key
Disabling protocol version 1. Could not load host key
Disabling protocol version 2. Could not load host key
sshd: no hostkeys available — exiting”
大致的意思就是需要某个key什么的。
问题所在：
    1、系统丢失了ssh_host_dsa_key和ssh_host_rsa_key
    2、用户没有权限访问这两个key

解决办法如下：
1、系统丢失了两个key时：

在终端中输入：ssh-keygen -t dsa -f /etc/ssh/ssh_host_dsa_key重新建立ssh_host_dsa_key文件
以下是返回信息

Generating public/private dsa key pair.
Enter passphrase (empty for no passphrase):（直接回车）
Enter same passphrase again:
Your identification has been saved in /etc/ssh/ssh_host_dsa_key.
Your public key has been saved in /etc/ssh/ssh_host_dsa_key.pub.
The key fingerprint is:
xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx root@localhost.localdomain
在终端中输入：ssh-keygen -t rsa -f /etc/ssh/ssh_host_rsa_key重新建立ssh_host_rsa_key文件
以下是返回信息
Generating public/private rkey pair.
Enter passphrase (empty for no passphrase):（直接回车）
Enter same passphrase again:
Your identification has been saved in /etc/ssh/ssh_host_rsa_key.
Your public key has been saved in /etc/ssh/ssh_host_dsa_rey.pub.
root@localhost.localdomain
现在用

/usr/sbin/sshd
即可成功启动sshd

这时候，就可以在windows底下使用putty连接这台linux主机了。
2、当前用户没有权限的时候用命令
/usr/sbin/sshd
启动sshd的时候也会这样，所以这是检查是否是root用户，一般root用户才能执行这个操作