diff --git a/sbin/disklabel/disklabel.c b/sbin/disklabel/disklabel.c
index 4a03c2202e5b..be8a8ee37cec 100644
--- a/sbin/disklabel/disklabel.c
+++ b/sbin/disklabel/disklabel.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: disklabel.c,v 1.79 1999/12/20 18:19:18 fair Exp $	*/
+/*	$NetBSD: disklabel.c,v 1.80 2000/01/18 00:02:28 perseant Exp $	*/
 
 /*
  * Copyright (c) 1987, 1993
@@ -47,7 +47,7 @@ __COPYRIGHT("@(#) Copyright (c) 1987, 1993\n\
 static char sccsid[] = "@(#)disklabel.c	8.4 (Berkeley) 5/4/95";
 /* from static char sccsid[] = "@(#)disklabel.c	1.2 (Symmetric) 11/28/85"; */
 #else
-__RCSID("$NetBSD: disklabel.c,v 1.79 1999/12/20 18:19:18 fair Exp $");
+__RCSID("$NetBSD: disklabel.c,v 1.80 2000/01/18 00:02:28 perseant Exp $");
 #endif
 #endif /* not lint */
 
@@ -1220,6 +1220,11 @@ showpartitions(f, lp)
 				break;
 
 			case FS_BSDLFS:
+				(void) fprintf(f, "    %5d %5d %5d ",
+				    pp->p_fsize, pp->p_fsize * pp->p_frag,
+				    pp->p_sgs);
+				break;
+
 			case FS_EX2FS:
 				(void) fprintf(f, "    %5d %5d       ",
 				    pp->p_fsize, pp->p_fsize * pp->p_frag);
@@ -1686,6 +1691,13 @@ getasciilabel(f, lp)
 				NXTNUM(pp->p_cpg);
 				break;
 			case FS_BSDLFS:
+				NXTNUM(pp->p_fsize);
+				if (pp->p_fsize == 0)
+					break;
+				NXTNUM(v);
+				pp->p_frag = v / pp->p_fsize;
+				NXTNUM(pp->p_sgs);
+				break;
 			case FS_EX2FS:
 				NXTNUM(pp->p_fsize);
 				if (pp->p_fsize == 0)
diff --git a/sbin/newfs_lfs/lfs.c b/sbin/newfs_lfs/lfs.c
index 66d0c4e8d9e4..0060c15d2b09 100644
--- a/sbin/newfs_lfs/lfs.c
+++ b/sbin/newfs_lfs/lfs.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: lfs.c,v 1.6 1999/11/05 18:59:12 perseant Exp $	*/
+/*	$NetBSD: lfs.c,v 1.7 2000/01/18 00:02:29 perseant Exp $	*/
 
 /*-
  * Copyright (c) 1991, 1993
@@ -38,11 +38,12 @@
 #if 0
 static char sccsid[] = "@(#)lfs.c	8.5 (Berkeley) 5/24/95";
 #else
-__RCSID("$NetBSD: lfs.c,v 1.6 1999/11/05 18:59:12 perseant Exp $");
+__RCSID("$NetBSD: lfs.c,v 1.7 2000/01/18 00:02:29 perseant Exp $");
 #endif
 #endif /* not lint */
 
 #include <sys/param.h>
+#define FSTYPENAMES
 #include <sys/disklabel.h>
 #include <sys/time.h>
 #include <sys/mount.h>
@@ -228,12 +229,21 @@ make_lfs(fd, lp, partp, minfree, block_size, frag_size, seg_size)
 
 	lfsp = &lfs_default;
 
+	/* If partition is not an LFS partition, warn that that is the case */
+	if(partp->p_fstype != FS_BSDLFS) {
+		fatal("partition label indicated fs type \"%s\", expected \"%s\"",
+		      fstypenames[partp->p_fstype], fstypenames[FS_BSDLFS]);
+	}
+
 	if (!(bsize = block_size))
-		bsize = DFL_LFSBLOCK;
+		if (!(bsize = partp->p_fsize * partp->p_frag))
+			bsize = DFL_LFSBLOCK;
 	if (!(fsize = frag_size))
-		fsize = DFL_LFSFRAG;
+		if (!(fsize = partp->p_frag))
+			fsize = DFL_LFSFRAG;
 	if (!(ssize = seg_size))
-		ssize = DFL_LFSSEG;
+		if (!(ssize = (partp->p_fsize * partp->p_frag) << partp->p_sgs))
+			ssize = DFL_LFSSEG;
 
 	/* Sanity check: fsize<=bsize<ssize */
 	if (fsize > bsize) {
@@ -242,8 +252,14 @@ make_lfs(fd, lp, partp, minfree, block_size, frag_size, seg_size)
 			fatal("fragment size must be <= block size %d", bsize);
 		fsize = bsize;
 	}
-	if (bsize >= ssize)
-		fatal("block size must be < segment size");
+	if (bsize >= ssize) {
+		/* Only fatal if ssize was explicitly set */
+		if(seg_size)
+			fatal("block size must be < segment size");
+		warnx("%s: disklabel segment size (%d) too small, using default (%d)",
+		      progname, ssize, DFL_LFSSEG);
+		ssize = DFL_LFSSEG;
+	}
 
     tryagain:
 	/* Modify parts of superblock overridden by command line arguments */
diff --git a/sbin/newfs_lfs/newfs_lfs.8 b/sbin/newfs_lfs/newfs_lfs.8
index eaaddeee3446..a7b72db1e118 100644
--- a/sbin/newfs_lfs/newfs_lfs.8
+++ b/sbin/newfs_lfs/newfs_lfs.8
@@ -1,4 +1,4 @@
-.\"	$NetBSD: newfs_lfs.8,v 1.3 2000/01/16 00:44:59 hubertf Exp $
+.\"	$NetBSD: newfs_lfs.8,v 1.4 2000/01/18 00:02:29 perseant Exp $
 .\"
 .\" Copyright (c) 1993
 .\"	The Regents of the University of California.  All rights reserved.
@@ -56,11 +56,19 @@ the proper fstype is 4.4LFS.)
 The following options define the general layout policies.
 .Bl -tag -width Fl
 .It Fl B
-The logical segment size of the file system in bytes.
+The logical segment size of the file system in bytes.  If not specified,
+the segment size is computed by left-shifting the partition label's block
+size by the amount indicated in the partition table's segshift.  (A reasonable
+value for the segshift field in the disklabel is 7, which gives 1M segments
+for 8K blocks.)
 .It Fl b Ar block-size
-The block size of the file system in bytes.
+The block size of the file system in bytes.  If not specified, the block
+size is taken from the partition label, or if the partition label
+indicates 0, a compile-time default of 8K is used.
 .It Fl f Ar fragment-size
-The fragment size of the file system in bytes.
+The fragment size of the file system in bytes.  If not specified,
+the fragment size is taken from the partition label, or if the partition
+label indicates 0, a compile-time default of 1K is used.
 .It Fl L
 Create a log-structured file system (LFS).  This is the default, and this
 option is provided for compatibility only.