如何清除linux 緩存??

我菜我怕誰

我用putty遠程登陸一臺開ssh服務的linux機器.聯(lián)結時候出現(xiàn)如下:

the server's host key is not cached in the registry . you have no guarantee that the server is the computer you think it is.
the server's rsa2 key fingerprint is : ssh-rsa 1024 34:43:45:d4:.....
if you trust this host, hit yes to add the key to pietty's cache and carry on connecting . if you want to carry on connecting just once ,without adding the key to the cache , hit No . if you do not trust this host , hit cancel to abandon the connection.

請問如果我選擇" YES"　，那么我怎么才能　清除linux 上的緩存，讓我的機器每次登陸這臺linux 都出現(xiàn)這個提示？？？
高手幫忙！�。≈x謝�。�！