make it clear that this is a destructive test

diff --git a/lustre-iokit/sgpdd-survey/README b/lustre-iokit/sgpdd-survey/README
index 78fa376..3666baf 100644 (file)
--- a/lustre-iokit/sgpdd-survey/README
+++ b/lustre-iokit/sgpdd-survey/README
@@ -1,3 +1,6 @@
+WARNING: Running sgp_dd will ERASE the contents of the disk devices.
+         This is NOT to be run on any OST where you care about any data
+        or you are not expecting to reformat the filesystem afterward.
 
 Requirements
 ------------