mention hdparm secure erase in retirement procedure

howto/retire-a-host.md

@@ -91,6 +91,13 @@ software might not work for SSDs. For now we use this:
 
     nwipe --autonuke --method=random --rounds=2 --verify=off /dev/nvme1n1
 
+TODO: consider `hdparm` and the "secure erase" procedure for SSDs:
+
+    hdparm --user-master u --security-set-pass Eins /dev/sdc
+    time hdparm --user-master u --security-erase Eins /dev/sdc
+
+See also [stressant documentation](https://stressant.readthedocs.io/en/latest/usage.html#wiping-disks) abnout this.
+
 When you return:
 
  1. start a `screen` session with a static `busybox` as your `SHELL`