--- mdadm-4.1/mdadm.c~	2018-12-12 17:15:41.359619760 +0800

+++ mdadm-4.1/mdadm.c	2018-12-12 17:16:09.265626436 +0800

@@ -1553,6 +1553,10 @@

 			c.delay = DEFAULT_BITMAP_DELAY;

 		if (c.nodes) {

+			pr_err("WARNING: bitmap=clustered is Technology Preview.\n");

+			pr_err("For more information on Technology Preview features, visit:\n");

+			pr_err("https://access.redhat.com/support/offerings/techpreview/ \n");

+

 			if (!s.bitmap_file ||

 			    strcmp(s.bitmap_file, "clustered") != 0) {

 				pr_err("--nodes argument only compatible with --bitmap=clustered\n");