diff --git a/secrets/secrets.nix b/secrets/secrets.nix
index 13d44df..ed2afd2 100644
--- a/secrets/secrets.nix
+++ b/secrets/secrets.nix
@@ -17,3 +17,6 @@
   "skydick-ldap-bind.age".publicKeys = [ admin skydick ];
   "skydick-samba-ldap-admin.age".publicKeys = [ admin skydick ];
 }
+
+# 重装系统一定要备份原机器的 ssh ed25519 私钥
+# 否则他妈的比bitlocker还傻逼