diff --git a/sys/cam/scsi/scsi_cd.c b/sys/cam/scsi/scsi_cd.c
index ac65e368ed63..f587b00a703c 100644
--- a/sys/cam/scsi/scsi_cd.c
+++ b/sys/cam/scsi/scsi_cd.c
@@ -2723,7 +2723,7 @@ cdcheckmedia(struct cam_periph *periph)
 
 	cdprevent(periph, PR_PREVENT);
 	softc->disk->d_maxsize = DFLTPHYS;
-	softc->disk->d_sectorsize = 0;
+	softc->disk->d_sectorsize = 2048;
 	softc->disk->d_mediasize = 0;
 
 	/*
diff --git a/sys/geom/geom_subr.c b/sys/geom/geom_subr.c
index c7058ea857fa..3085c4bf0be6 100644
--- a/sys/geom/geom_subr.c
+++ b/sys/geom/geom_subr.c
@@ -706,6 +706,9 @@ g_access(struct g_consumer *cp, int dcr, int dcw, int dce)
 		cp->acr += dcr;
 		cp->acw += dcw;
 		cp->ace += dce;
+		if (pp->acr != 0 || pp->acw != 0 || pp->ace != 0)
+			KASSERT(pp->sectorsize > 0,
+			    ("Provider %s lacks sectorsize", pp->name));
 	}
 	return (error);
 }
diff --git a/sys/geom/notes b/sys/geom/notes
index 3b0f811f091f..4fcacaefbc40 100644
--- a/sys/geom/notes
+++ b/sys/geom/notes
@@ -138,3 +138,13 @@ application     |      |          |          |    X     |  X     |
 geom_slice.h is special in that it documents a "library" for implementing
 a specific kind of class, and consequently does not appear in the above
 matrix.
+-----------------------------------------------------------------------
+Removable media.
+
+In general, the theory is that a drive creates the provider when it has
+a media and destroys it when the media disappears.
+
+In a more realistic world, we will allow a provider to be opened medialess
+(set any sectorsize and a mediasize==0) in order to allow operations like
+open/close tray etc.
+