diff --git a/sys/arch/acorn32/mainbus/fd.c b/sys/arch/acorn32/mainbus/fd.c
index 8eeef7519e3b..f2a72dc3405d 100644
--- a/sys/arch/acorn32/mainbus/fd.c
+++ b/sys/arch/acorn32/mainbus/fd.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: fd.c,v 1.25 2006/03/26 04:32:33 thorpej Exp $	*/
+/*	$NetBSD: fd.c,v 1.26 2006/04/14 13:09:05 blymn Exp $	*/
 
 /*-
  * Copyright (c) 1998 The NetBSD Foundation, Inc.
@@ -89,7 +89,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: fd.c,v 1.25 2006/03/26 04:32:33 thorpej Exp $");
+__KERNEL_RCSID(0, "$NetBSD: fd.c,v 1.26 2006/04/14 13:09:05 blymn Exp $");
 
 #include "opt_ddb.h"
 
@@ -1030,7 +1030,7 @@ loop:
 		fd->sc_cylin = -1;
 		fdc->sc_state = SEEKWAIT;
 
-		fd->sc_dk.dk_seek++;
+		iostat_seek(fd->sc_dk.dk_stats);
 		disk_busy(&fd->sc_dk);
 
 		callout_reset(&fdc->sc_timo_ch, 4 * hz, fdctimeout, fdc);
diff --git a/sys/arch/arc/jazz/fd.c b/sys/arch/arc/jazz/fd.c
index 4764745c0c8a..0307b415cab8 100644
--- a/sys/arch/arc/jazz/fd.c
+++ b/sys/arch/arc/jazz/fd.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: fd.c,v 1.25 2006/02/23 05:37:46 thorpej Exp $	*/
+/*	$NetBSD: fd.c,v 1.26 2006/04/14 13:09:05 blymn Exp $	*/
 /*	$OpenBSD: fd.c,v 1.6 1998/10/03 21:18:57 millert Exp $	*/
 /*	NetBSD: fd.c,v 1.78 1995/07/04 07:23:09 mycroft Exp 	*/
 
@@ -73,7 +73,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: fd.c,v 1.25 2006/02/23 05:37:46 thorpej Exp $");
+__KERNEL_RCSID(0, "$NetBSD: fd.c,v 1.26 2006/04/14 13:09:05 blymn Exp $");
 
 #include <sys/param.h>
 #include <sys/systm.h>
@@ -831,7 +831,7 @@ loop:
 		fd->sc_cylin = -1;
 		fdc->sc_state = SEEKWAIT;
 
-		fd->sc_dk.dk_seek++;
+		iostat_seek(fd->sc_dk.dk_stats);
 		disk_busy(&fd->sc_dk);
 
 		callout_reset(&fdc->sc_timo_ch, 4 * hz, fdctimeout, fdc);
diff --git a/sys/arch/atari/dev/hdfd.c b/sys/arch/atari/dev/hdfd.c
index a70a985f4780..489f88f38a66 100644
--- a/sys/arch/atari/dev/hdfd.c
+++ b/sys/arch/atari/dev/hdfd.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: hdfd.c,v 1.49 2006/02/23 05:37:46 thorpej Exp $	*/
+/*	$NetBSD: hdfd.c,v 1.50 2006/04/14 13:09:05 blymn Exp $	*/
 
 /*-
  * Copyright (c) 1996 Leo Weppelman
@@ -91,7 +91,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: hdfd.c,v 1.49 2006/02/23 05:37:46 thorpej Exp $");
+__KERNEL_RCSID(0, "$NetBSD: hdfd.c,v 1.50 2006/04/14 13:09:05 blymn Exp $");
 
 #include "opt_ddb.h"
 
@@ -1050,7 +1050,7 @@ loop:
 		fd->sc_cylin = -1;
 		fdc->sc_state = SEEKWAIT;
 
-		fd->sc_dk.dk_seek++;
+		iostat_seek(fd->sc_dk.dk_stats);
 		disk_busy(&fd->sc_dk);
 
 		callout_reset(&fdc->sc_timo_ch, 4 * hz, fdctimeout, fdc);
diff --git a/sys/arch/hp300/dev/rd.c b/sys/arch/hp300/dev/rd.c
index 84b01717ecda..769137396f77 100644
--- a/sys/arch/hp300/dev/rd.c
+++ b/sys/arch/hp300/dev/rd.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: rd.c,v 1.73 2006/03/29 16:03:37 tsutsui Exp $	*/
+/*	$NetBSD: rd.c,v 1.74 2006/04/14 13:09:05 blymn Exp $	*/
 
 /*-
  * Copyright (c) 1996, 1997 The NetBSD Foundation, Inc.
@@ -117,7 +117,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: rd.c,v 1.73 2006/03/29 16:03:37 tsutsui Exp $");
+__KERNEL_RCSID(0, "$NetBSD: rd.c,v 1.74 2006/04/14 13:09:05 blymn Exp $");
 
 #include "opt_useleds.h"
 #include "rnd.h"
@@ -836,7 +836,7 @@ again:
 
 		/* Instrumentation. */
 		disk_busy(&rs->sc_dkdev);
-		rs->sc_dkdev.dk_seek++;
+		iostat_seek(rs->sc_dkdev.dk_stats);
 
 #ifdef DEBUG
 		if (rddebug & RDB_IO)
diff --git a/sys/arch/pdp10/dev/hp.c b/sys/arch/pdp10/dev/hp.c
index e5e9201be0e2..ebebd5439e6b 100644
--- a/sys/arch/pdp10/dev/hp.c
+++ b/sys/arch/pdp10/dev/hp.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: hp.c,v 1.5 2006/03/28 17:38:26 thorpej Exp $ */
+/*	$NetBSD: hp.c,v 1.6 2006/04/14 13:09:05 blymn Exp $ */
 /*
  * Copyright (c) 1996 Ludd, University of Lule}, Sweden.
  * All rights reserved.
@@ -265,7 +265,7 @@ hpstart(struct	rh_device *md)
 	 * Collect statistics.
 	 */
 	disk_busy(&sc->sc_disk);
-	sc->sc_disk.dk_seek++;
+	iostat_seek(sc->sc_disk.dk_stats);
 
 	bn = bp->b_rawblkno;
 	if (bn) {
diff --git a/sys/arch/sparc/dev/fd.c b/sys/arch/sparc/dev/fd.c
index 8409a9c5699a..8a889c1fe855 100644
--- a/sys/arch/sparc/dev/fd.c
+++ b/sys/arch/sparc/dev/fd.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: fd.c,v 1.125 2006/02/23 05:37:48 thorpej Exp $	*/
+/*	$NetBSD: fd.c,v 1.126 2006/04/14 13:09:05 blymn Exp $	*/
 
 /*-
  * Copyright (c) 2000 The NetBSD Foundation, Inc.
@@ -108,7 +108,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: fd.c,v 1.125 2006/02/23 05:37:48 thorpej Exp $");
+__KERNEL_RCSID(0, "$NetBSD: fd.c,v 1.126 2006/04/14 13:09:05 blymn Exp $");
 
 #include "opt_ddb.h"
 #include "opt_md.h"
@@ -1490,7 +1490,7 @@ loop:
 		fdc->sc_state = SEEKWAIT;
 		fdc->sc_nstat = 0;
 
-		fd->sc_dk.dk_seek++;
+		iostat_seek(fd->sc_dk.dk_stats);
 
 		disk_busy(&fd->sc_dk);
 		callout_reset(&fdc->sc_timo_ch, 4 * hz, fdctimeout, fdc);
diff --git a/sys/arch/sparc/dev/tctrl.c b/sys/arch/sparc/dev/tctrl.c
index 38eec15c8d2a..4d2fa34f6fcf 100644
--- a/sys/arch/sparc/dev/tctrl.c
+++ b/sys/arch/sparc/dev/tctrl.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: tctrl.c,v 1.31 2006/03/08 01:17:49 macallan Exp $	*/
+/*	$NetBSD: tctrl.c,v 1.32 2006/04/14 13:09:05 blymn Exp $	*/
 
 /*-
  * Copyright (c) 1998, 2005, 2006 The NetBSD Foundation, Inc.
@@ -37,7 +37,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: tctrl.c,v 1.31 2006/03/08 01:17:49 macallan Exp $");
+__KERNEL_RCSID(0, "$NetBSD: tctrl.c,v 1.32 2006/04/14 13:09:05 blymn Exp $");
 
 #include <sys/param.h>
 #include <sys/systm.h>
@@ -1532,18 +1532,18 @@ tctrl_event_thread(void *v)
 			tsleep(&sc->sc_events, PWAIT, "probe_disk", hz);
 	}			
 	printf("found %s\n", sd->sc_dev.dv_xname);
-	rcount = sd->sc_dk.dk_rxfer;
-	wcount = sd->sc_dk.dk_wxfer;
+	rcount = sd->sc_dk.dk_stats->rxfer;
+	wcount = sd->sc_dk.dk_stats->wxfer;
 
 	tctrl_read_event_status(sc);
 	
 	while (1) {
 		tsleep(&sc->sc_events, PWAIT, "tctrl_event", ticks);
 		s = splhigh();
-		if ((rcount != sd->sc_dk.dk_rxfer) || 
-		    (wcount != sd->sc_dk.dk_wxfer)) {
-			rcount = sd->sc_dk.dk_rxfer;
-			wcount = sd->sc_dk.dk_wxfer;
+		if ((rcount != sd->sc_dk.dk_stats->rxfer) || 
+		    (wcount != sd->sc_dk.dk_stats->wxfer)) {
+			rcount = sd->sc_dk.dk_stats->rxfer;
+			wcount = sd->sc_dk.dk_stats->wxfer;
 			sc->sc_lcdwanted |= TS102_LCD_DISK_ACTIVE;
 		} else
 			sc->sc_lcdwanted &= ~TS102_LCD_DISK_ACTIVE;
diff --git a/sys/arch/vax/mba/hp.c b/sys/arch/vax/mba/hp.c
index 678ea0931ddd..64929bfdb085 100644
--- a/sys/arch/vax/mba/hp.c
+++ b/sys/arch/vax/mba/hp.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: hp.c,v 1.40 2006/03/28 17:38:28 thorpej Exp $ */
+/*	$NetBSD: hp.c,v 1.41 2006/04/14 13:09:05 blymn Exp $ */
 /*
  * Copyright (c) 1996 Ludd, University of Lule}, Sweden.
  * All rights reserved.
@@ -42,7 +42,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: hp.c,v 1.40 2006/03/28 17:38:28 thorpej Exp $");
+__KERNEL_RCSID(0, "$NetBSD: hp.c,v 1.41 2006/04/14 13:09:05 blymn Exp $");
 
 #include <sys/param.h>
 #include <sys/systm.h>
@@ -235,7 +235,7 @@ hpstart(struct	mba_device *md)
 	 * Collect statistics.
 	 */
 	disk_busy(&sc->sc_disk);
-	sc->sc_disk.dk_seek++;
+	iostat_seek(sc->sc_disk->dk_stats);
 
 	bn = bp->b_rawblkno;
 	if (bn) {
diff --git a/sys/arch/x68k/dev/fd.c b/sys/arch/x68k/dev/fd.c
index 69575fc3a966..3c9100fddb82 100644
--- a/sys/arch/x68k/dev/fd.c
+++ b/sys/arch/x68k/dev/fd.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: fd.c,v 1.69 2006/03/28 17:38:28 thorpej Exp $	*/
+/*	$NetBSD: fd.c,v 1.70 2006/04/14 13:09:06 blymn Exp $	*/
 
 /*-
  * Copyright (c) 1998 The NetBSD Foundation, Inc.
@@ -71,7 +71,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: fd.c,v 1.69 2006/03/28 17:38:28 thorpej Exp $");
+__KERNEL_RCSID(0, "$NetBSD: fd.c,v 1.70 2006/04/14 13:09:06 blymn Exp $");
 
 #include "rnd.h"
 #include "opt_ddb.h"
@@ -1109,7 +1109,7 @@ loop:
 		fd->sc_cylin = -1;
 		fdc->sc_state = SEEKWAIT;
 
-		fd->sc_dk.dk_seek++;
+		iostat_seek(fd->sc_dk.dk_stats);
 		disk_busy(&fd->sc_dk);
 
 		callout_reset(&fdc->sc_timo_ch, 4 * hz, fdctimeout, fdc);
diff --git a/sys/conf/files b/sys/conf/files
index 35c535a3d386..2bea8cbdd7f2 100644
--- a/sys/conf/files
+++ b/sys/conf/files
@@ -1,4 +1,4 @@
-#	$NetBSD: files,v 1.769 2006/04/07 18:55:22 riz Exp $
+#	$NetBSD: files,v 1.770 2006/04/14 13:09:06 blymn Exp $
 
 #	@(#)files.newconf	7.5 (Berkeley) 5/10/93
 
@@ -1250,6 +1250,7 @@ file	kern/subr_blist.c		vmswap
 file	kern/subr_bufq.c
 file	kern/subr_devsw.c
 file	kern/subr_disk.c
+file	kern/subr_iostat.c
 file	kern/subr_evcnt.c
 file	kern/subr_extent.c
 file	kern/subr_log.c
diff --git a/sys/dev/gpib/rd.c b/sys/dev/gpib/rd.c
index b3a1a58d9477..a23516820d42 100644
--- a/sys/dev/gpib/rd.c
+++ b/sys/dev/gpib/rd.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: rd.c,v 1.11 2006/03/29 06:33:50 thorpej Exp $ */
+/*	$NetBSD: rd.c,v 1.12 2006/04/14 13:09:06 blymn Exp $ */
 
 /*-
  * Copyright (c) 1996-2003 The NetBSD Foundation, Inc.
@@ -118,7 +118,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: rd.c,v 1.11 2006/03/29 06:33:50 thorpej Exp $");
+__KERNEL_RCSID(0, "$NetBSD: rd.c,v 1.12 2006/04/14 13:09:06 blymn Exp $");
 
 #include "rnd.h"
 
@@ -785,7 +785,7 @@ again:
 	    sizeof(sc->sc_ioc)-1) == sizeof(sc->sc_ioc)-1) {
 		/* Instrumentation. */
 		disk_busy(&sc->sc_dk);
-		sc->sc_dk.dk_seek++;
+		iostat_seek(sc->sc_dk.dk_stats);
 		gpibawait(sc->sc_ic);
 		return;
 	}
diff --git a/sys/dev/isa/fd.c b/sys/dev/isa/fd.c
index ccec0315632f..d8e2a5ecd202 100644
--- a/sys/dev/isa/fd.c
+++ b/sys/dev/isa/fd.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: fd.c,v 1.66 2006/03/28 17:38:34 thorpej Exp $	*/
+/*	$NetBSD: fd.c,v 1.67 2006/04/14 13:09:06 blymn Exp $	*/
 
 /*-
  * Copyright (c) 1998, 2003 The NetBSD Foundation, Inc.
@@ -88,7 +88,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: fd.c,v 1.66 2006/03/28 17:38:34 thorpej Exp $");
+__KERNEL_RCSID(0, "$NetBSD: fd.c,v 1.67 2006/04/14 13:09:06 blymn Exp $");
 
 #include "rnd.h"
 #include "opt_ddb.h"
@@ -1043,7 +1043,7 @@ loop:
 		fd->sc_cylin = -1;
 		fdc->sc_state = SEEKWAIT;
 
-		fd->sc_dk.dk_seek++;
+		iostat_seek(fd->sc_dk.dk_stats);
 		disk_busy(&fd->sc_dk);
 
 		callout_reset(&fdc->sc_timo_ch, 4 * hz, fdctimeout, fdc);
diff --git a/sys/dev/scsipi/st.c b/sys/dev/scsipi/st.c
index b5114fe02303..6de4f1cee0c1 100644
--- a/sys/dev/scsipi/st.c
+++ b/sys/dev/scsipi/st.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: st.c,v 1.188 2006/03/30 16:09:28 thorpej Exp $ */
+/*	$NetBSD: st.c,v 1.189 2006/04/14 13:09:06 blymn Exp $ */
 
 /*-
  * Copyright (c) 1998, 2004 The NetBSD Foundation, Inc.
@@ -57,7 +57,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: st.c,v 1.188 2006/03/30 16:09:28 thorpej Exp $");
+__KERNEL_RCSID(0, "$NetBSD: st.c,v 1.189 2006/04/14 13:09:06 blymn Exp $");
 
 #include "opt_scsi.h"
 
@@ -76,7 +76,7 @@ __KERNEL_RCSID(0, "$NetBSD: st.c,v 1.188 2006/03/30 16:09:28 thorpej Exp $");
 #include <sys/conf.h>
 #include <sys/kernel.h>
 #include <sys/vnode.h>
-#include <sys/tape.h>
+#include <sys/iostat.h>
 #include <sys/sysctl.h>
 
 #include <dev/scsipi/scsi_spc.h>
@@ -107,9 +107,6 @@ __KERNEL_RCSID(0, "$NetBSD: st.c,v 1.188 2006/03/30 16:09:28 thorpej Exp $");
 #define		ST_MOUNT_DELAY		0
 #endif
 
-struct tape *
-drive_attach(char *name);
-
 static dev_type_open(stopen);
 static dev_type_close(stclose);
 static dev_type_read(stread);
@@ -352,14 +349,6 @@ static const struct scsipi_periphsw st_switch = {
 	stdone
 };
 
-/*
- * A global list of all tape drives attached to the system.  May grow or
- * shrink over time.
- */
-struct  tapelist_head tapelist = TAILQ_HEAD_INITIALIZER(tapelist);
-int     tape_count = 0;             /* number of drives in global tapelist */
-struct simplelock tapelist_slock = SIMPLELOCK_INITIALIZER;
-
 #if	defined(ST_ENABLE_EARLYWARN)
 #define	ST_INIT_FLAGS	ST_EARLYWARN
 #else
@@ -423,8 +412,9 @@ stattach(struct device *parent, struct st_softc *st, void *aux)
 		    (st->flags & ST_READONLY) ? "protected" : "enabled");
 	}
 
-	st->stats = drive_attach(st->sc_dev.dv_xname);
-	
+	st->stats = iostat_alloc(IOSTAT_TAPE);
+	st->stats->name = st->sc_dev.dv_xname;
+
 #if NRND > 0
 	rnd_attach_source(&st->rnd_source, st->sc_dev.dv_xname,
 			  RND_TYPE_TAPE, 0);
@@ -480,16 +470,7 @@ stdetach(struct device *self, int flags)
 	vdevgone(bmaj, mn, mn+STNMINOR-1, VBLK);
 	vdevgone(cmaj, mn, mn+STNMINOR-1, VCHR);
 
-	if (tape_count == 0) {
-		printf("%s detach: tape_count already zero\n",
-		       st->sc_dev.dv_xname);
-	} else {
-		simple_lock(&tapelist_slock);
-		TAILQ_REMOVE(&tapelist, st->stats, link);
-		tape_count--;
-		simple_unlock(&tapelist_slock);
-		free(st->stats, M_DEVBUF);
-	}
+	iostat_free(st->stats);
 
 #if NRND > 0
 	/* Unhook the entropy source. */
@@ -1187,7 +1168,7 @@ ststart(struct scsipi_periph *periph)
 	struct buf *bp;
 	struct scsi_rw_tape cmd;
 	struct scsipi_xfer *xs;
-	int flags, error, s;
+	int flags, error;
 
 	SC_DEBUG(periph, SCSIPI_DB2, ("ststart "));
 	/*
@@ -1224,12 +1205,8 @@ ststart(struct scsipi_periph *periph)
 		if ((bp = BUFQ_PEEK(st->buf_queue)) == NULL)
 			return;
 
-		if (st->stats->busy++ == 0) {
-			s = splclock();
-			st->stats->timestamp = mono_time;
-			splx(s);
-		}
-		
+		iostat_busy(st->stats);
+
 		/*
 		 * only FIXEDBLOCK devices have pending I/O or space operations.
 		 */
@@ -1356,8 +1333,6 @@ stdone(struct scsipi_xfer *xs, int error)
 {
 	struct st_softc *st = (void *)xs->xs_periph->periph_dev;
 	struct buf *bp = xs->bp;
-	int s;
-	struct timeval st_time, diff_time;
 
 	if (bp) {
 		bp->b_error = error;
@@ -1370,32 +1345,10 @@ stdone(struct scsipi_xfer *xs, int error)
 		else
 			st->flags &= ~ST_WRITTEN;
 
-		if (st->stats->busy-- == 0) {
-			  /* this is not really fatal so we don't panic */
-			printf("%s: busy < 0, Oops.\n", st->stats->name);
-			st->stats->busy = 0;
-		} else {
-			s = splclock();
-			st_time = mono_time;
-			splx(s);
+		iostat_unbusy(st->stats, bp->b_bcount,
+			     ((bp->b_flags & B_READ) == B_READ));
 
-			timersub(&st_time, &st->stats->timestamp, &diff_time);
-			timeradd(&st->stats->time, &diff_time,
-				 &st->stats->time);
 
-			st->stats->timestamp = st_time;
-			if (bp->b_bcount > 0) {
-				if ((bp->b_flags & B_READ) == B_WRITE) {
-					st->stats->wbytes += bp->b_bcount;
-					st->stats->wxfer++;
-				} else {
-					st->stats->rbytes += bp->b_bcount;
-					st->stats->rxfer++;
-				}
-			}
-		}
-		
-			
 #if NRND > 0
 		rnd_add_uint32(&st->rnd_source, bp->b_blkno);
 #endif
@@ -2453,156 +2406,3 @@ stdump(dev_t dev, daddr_t blkno, caddr_t va, size_t size)
 	/* Not implemented. */
 	return (ENXIO);
 }
-
-int
-sysctl_hw_tapenames(SYSCTLFN_ARGS)
-{
-	char bf[TAPENAMELEN + 1];
-	char *where = oldp;
-	struct tape *tapep;
-	size_t needed, left, slen;
-	int error, first;
-
-	if (newp != NULL)
-		return (EPERM);
-	if (namelen != 0)
-		return (EINVAL);
-
-	first = 1;
-	error = 0;
-	needed = 0;
-	left = *oldlenp;
-
-	simple_lock(&tapelist_slock);
-	for (tapep = TAILQ_FIRST(&tapelist); tapep != NULL;
-	    tapep = TAILQ_NEXT(tapep, link)) {
-		if (where == NULL)
-			needed += strlen(tapep->name) + 1;
-		else {
-			memset(bf, 0, sizeof(bf));
-			if (first) {
-				strncpy(bf, tapep->name, sizeof(bf));
-				first = 0;
-			} else {
-				bf[0] = ' ';
-				strncpy(bf + 1, tapep->name, sizeof(bf) - 1);
-			}
-			bf[TAPENAMELEN] = '\0';
-			slen = strlen(bf);
-			if (left < slen + 1)
-				break;
-			/* +1 to copy out the trailing NUL byte */
-			error = copyout(bf, where, slen + 1);
-			if (error)
-				break;
-			where += slen;
-			needed += slen;
-			left -= slen;
-		}
-	}
-	simple_unlock(&tapelist_slock);
-	*oldlenp = needed;
-	return (error);
-}
-
-int
-sysctl_hw_tapestats(SYSCTLFN_ARGS)
-{
-	struct tape_sysctl stape;
-	struct tape *tapep;
-	char *where = oldp;
-	size_t tocopy, left;
-	int error;
-
-	if (newp != NULL)
-		return (EPERM);
-
-	tocopy = name[0];
-
-	if (where == NULL) {
-		*oldlenp = tape_count * tocopy;
-		return (0);
-	}
-
-	error = 0;
-	left = *oldlenp;
-	memset(&stape, 0, sizeof(stape));
-	*oldlenp = 0;
-
-	simple_lock(&tapelist_slock);
-	TAILQ_FOREACH(tapep, &tapelist, link) {
-		if (left < tocopy)
-			break;
-		strncpy(stape.name, tapep->name, sizeof(stape.name));
-		stape.xfer = tapep->rxfer + tapep->wxfer;
-		stape.rxfer = tapep->rxfer;
-		stape.wxfer = tapep->wxfer;
-		stape.bytes = tapep->rbytes + tapep->wbytes;
-		stape.rbytes = tapep->rbytes;
-		stape.wbytes = tapep->wbytes;
-		stape.attachtime_sec = tapep->attachtime.tv_sec;
-		stape.attachtime_usec = tapep->attachtime.tv_usec;
-		stape.timestamp_sec = tapep->timestamp.tv_sec;
-		stape.timestamp_usec = tapep->timestamp.tv_usec;
-		stape.time_sec = tapep->time.tv_sec;
-		stape.time_usec = tapep->time.tv_usec;
-		stape.busy = tapep->busy;
-
-		error = copyout(&stape, where, min(tocopy, sizeof(stape)));
-		if (error)
-			break;
-		where += tocopy;
-		*oldlenp += tocopy;
-		left -= tocopy;
-	}
-	simple_unlock(&tapelist_slock);
-	return (error);
-}
-
-struct tape *
-drive_attach(char *name) 
-{
-	struct tape *stats;
-	int s;
-	
-	/* Allocate and initialise statistics */
-	stats = (struct tape *) malloc(sizeof(struct tape), M_DEVBUF,
-					   M_WAITOK);
-	stats->rxfer = stats->wxfer = stats->rbytes = 0;
-	stats->wbytes = stats->busy = 0;
-
-	/*
-	 * Set the attached timestamp.
-	 */
-	s = splclock();
-	stats->attachtime = mono_time;
-	splx(s);
-
-	  /* and clear the utilisation time */
-	timerclear(&stats->time);
-
-	  /* link the tape drive to the tapelist */
-	simple_lock(&tapelist_slock);
-	TAILQ_INSERT_TAIL(&tapelist, stats, link);
-	tape_count++;
-	simple_unlock(&tapelist_slock);
-	stats->name = name;
-
-	return stats;
-}
-
-SYSCTL_SETUP(sysctl_tape_stats_setup, "sysctl tape stats setup")
-{
-	sysctl_createv(clog, 0, NULL, NULL,
-		       CTLFLAG_PERMANENT,
-		       CTLTYPE_STRING, "tapenames",
-		       SYSCTL_DESCR("List of tape devices present"),
-		       sysctl_hw_tapenames, 0, NULL, 0,
-		       CTL_HW, HW_TAPENAMES, CTL_EOL);
-	sysctl_createv(clog, 0, NULL, NULL,
-		       CTLFLAG_PERMANENT,
-		       CTLTYPE_STRUCT, "tapestats",
-		       SYSCTL_DESCR("Statistics on tape drive operation"),
-		       sysctl_hw_tapestats, 0, NULL, 0,
-		       CTL_HW, HW_TAPESTATS, CTL_EOL);
-}
diff --git a/sys/dev/scsipi/stvar.h b/sys/dev/scsipi/stvar.h
index 32bdb6e4c347..375b816b7389 100644
--- a/sys/dev/scsipi/stvar.h
+++ b/sys/dev/scsipi/stvar.h
@@ -1,4 +1,4 @@
-/*	$NetBSD: stvar.h,v 1.16 2005/12/11 12:23:51 christos Exp $ */
+/*	$NetBSD: stvar.h,v 1.17 2006/04/14 13:09:06 blymn Exp $ */
 
 /*-
  * Copyright (c) 1998 The NetBSD Foundation, Inc.
@@ -150,9 +150,9 @@ struct st_softc {
 					/* operations */
 	struct callout sc_callout;	/* restarting the queue after */
 					/* transient error */
-	
-	struct tape *stats;		/* statistics for the drive */
-	
+
+	struct io_stats *stats;		/* statistics for the drive */
+
 #if NRND > 0
 	rndsource_element_t	rnd_source;
 #endif
diff --git a/sys/kern/init_sysctl.c b/sys/kern/init_sysctl.c
index 0c8c34a7ffed..729e7f892ab5 100644
--- a/sys/kern/init_sysctl.c
+++ b/sys/kern/init_sysctl.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: init_sysctl.c,v 1.65 2006/04/01 00:57:34 christos Exp $ */
+/*	$NetBSD: init_sysctl.c,v 1.66 2006/04/14 13:09:06 blymn Exp $ */
 
 /*-
  * Copyright (c) 2003 The NetBSD Foundation, Inc.
@@ -37,7 +37,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: init_sysctl.c,v 1.65 2006/04/01 00:57:34 christos Exp $");
+__KERNEL_RCSID(0, "$NetBSD: init_sysctl.c,v 1.66 2006/04/14 13:09:06 blymn Exp $");
 
 #include "opt_sysv.h"
 #include "opt_multiprocessor.h"
@@ -913,18 +913,6 @@ SYSCTL_SETUP(sysctl_hw_setup, "sysctl hw subtree setup")
 		       SYSCTL_DESCR("Software page size"),
 		       NULL, PAGE_SIZE, NULL, 0,
 		       CTL_HW, HW_PAGESIZE, CTL_EOL);
-	sysctl_createv(clog, 0, NULL, NULL,
-		       CTLFLAG_PERMANENT,
-		       CTLTYPE_STRING, "disknames",
-		       SYSCTL_DESCR("List of disk devices present"),
-		       sysctl_hw_disknames, 0, NULL, 0,
-		       CTL_HW, HW_DISKNAMES, CTL_EOL);
-	sysctl_createv(clog, 0, NULL, NULL,
-		       CTLFLAG_PERMANENT,
-		       CTLTYPE_STRUCT, "diskstats",
-		       SYSCTL_DESCR("Statistics on disk operation"),
-		       sysctl_hw_diskstats, 0, NULL, 0,
-		       CTL_HW, HW_DISKSTATS, CTL_EOL);
 	sysctl_createv(clog, 0, NULL, NULL,
 		       CTLFLAG_PERMANENT,
 		       CTLTYPE_STRING, "machine_arch",
diff --git a/sys/kern/subr_disk.c b/sys/kern/subr_disk.c
index c5e474a07124..c2af47c9dbbc 100644
--- a/sys/kern/subr_disk.c
+++ b/sys/kern/subr_disk.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: subr_disk.c,v 1.73 2005/12/26 18:45:27 perry Exp $	*/
+/*	$NetBSD: subr_disk.c,v 1.74 2006/04/14 13:09:06 blymn Exp $	*/
 
 /*-
  * Copyright (c) 1996, 1997, 1999, 2000 The NetBSD Foundation, Inc.
@@ -74,7 +74,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: subr_disk.c,v 1.73 2005/12/26 18:45:27 perry Exp $");
+__KERNEL_RCSID(0, "$NetBSD: subr_disk.c,v 1.74 2006/04/14 13:09:06 blymn Exp $");
 
 #include "opt_compat_netbsd.h"
 
@@ -88,14 +88,6 @@ __KERNEL_RCSID(0, "$NetBSD: subr_disk.c,v 1.73 2005/12/26 18:45:27 perry Exp $")
 #include <sys/sysctl.h>
 #include <lib/libkern/libkern.h>
 
-/*
- * A global list of all disks attached to the system.  May grow or
- * shrink over time.
- */
-struct	disklist_head disklist = TAILQ_HEAD_INITIALIZER(disklist);
-int	disk_count;		/* number of drives in global disklist */
-struct simplelock disklist_slock = SIMPLELOCK_INITIALIZER;
-
 /*
  * Compute checksum for disk label.
  */
@@ -172,27 +164,20 @@ diskerr(const struct buf *bp, const char *dname, const char *what, int pri,
 }
 
 /*
- * Searches the disklist for the disk corresponding to the
+ * Searches the iostatlist for the disk corresponding to the
  * name provided.
  */
 struct disk *
 disk_find(char *name)
 {
-	struct disk *diskp;
+	struct io_stats *stat;
 
-	if ((name == NULL) || (disk_count <= 0))
-		return (NULL);
+	stat = iostat_find(name);
 
-	simple_lock(&disklist_slock);
-	for (diskp = TAILQ_FIRST(&disklist); diskp != NULL;
-	    diskp = TAILQ_NEXT(diskp, dk_link))
-		if (strcmp(diskp->dk_name, name) == 0) {
-			simple_unlock(&disklist_slock);
-			return (diskp);
-		}
-	simple_unlock(&disklist_slock);
+	if ((stat != NULL) && (stat->type == IOSTAT_DISK))
+		return stat->parent;
 
-	return (NULL);
+        return (NULL);
 }
 
 static void
@@ -211,8 +196,6 @@ disk_init0(struct disk *diskp)
 static void
 disk_attach0(struct disk *diskp)
 {
-	int s;
-
 	/*
 	 * Allocate and initialize the disklabel structures.  Note that
 	 * it's not safe to sleep here, since we're probably going to be
@@ -228,19 +211,12 @@ disk_attach0(struct disk *diskp)
 	memset(diskp->dk_cpulabel, 0, sizeof(struct cpu_disklabel));
 
 	/*
-	 * Set the attached timestamp.
+	 * Set up the stats collection.
 	 */
-	s = splclock();
-	diskp->dk_attachtime = mono_time;
-	splx(s);
+	diskp->dk_stats = iostat_alloc(IOSTAT_DISK);
+        diskp->dk_stats->parent = (void *) diskp;
+        diskp->dk_stats->name = diskp->dk_name;
 
-	/*
-	 * Link into the disklist.
-	 */
-	simple_lock(&disklist_slock);
-	TAILQ_INSERT_TAIL(&disklist, diskp, dk_link);
-	disk_count++;
-	simple_unlock(&disklist_slock);
 }
 
 static void
@@ -248,14 +224,9 @@ disk_detach0(struct disk *diskp)
 {
 
 	/*
-	 * Remove from the disklist.
+	 * Remove from the drivelist.
 	 */
-	if (disk_count == 0)
-		panic("disk_detach: disk_count == 0");
-	simple_lock(&disklist_slock);
-	TAILQ_REMOVE(&disklist, diskp, dk_link);
-	disk_count--;
-	simple_unlock(&disklist_slock);
+        iostat_free(diskp->dk_stats);
 
 	/*
 	 * Free the space used by the disklabel structures.
@@ -316,205 +287,22 @@ pseudo_disk_detach(struct disk *diskp)
 	disk_detach0(diskp);
 }
 
-
 /*
- * Increment a disk's busy counter.  If the counter is going from
- * 0 to 1, set the timestamp.
+ * Mark the disk as busy for metrics collection.
  */
 void
 disk_busy(struct disk *diskp)
 {
-	int s;
-
-	/*
-	 * XXX We'd like to use something as accurate as microtime(),
-	 * but that doesn't depend on the system TOD clock.
-	 */
-	if (diskp->dk_busy++ == 0) {
-		s = splclock();
-		diskp->dk_timestamp = mono_time;
-		splx(s);
-	}
+	iostat_busy(diskp->dk_stats);
 }
 
 /*
- * Decrement a disk's busy counter, increment the byte count, total busy
- * time, and reset the timestamp.
+ * Finished disk operations, gather metrics.
  */
 void
 disk_unbusy(struct disk *diskp, long bcount, int read)
 {
-	int s;
-	struct timeval dv_time, diff_time;
-
-	if (diskp->dk_busy-- == 0) {
-		printf("%s: dk_busy < 0\n", diskp->dk_name);
-		panic("disk_unbusy");
-	}
-
-	s = splclock();
-	dv_time = mono_time;
-	splx(s);
-
-	timersub(&dv_time, &diskp->dk_timestamp, &diff_time);
-	timeradd(&diskp->dk_time, &diff_time, &diskp->dk_time);
-
-	diskp->dk_timestamp = dv_time;
-	if (bcount > 0) {
-		if (read) {
-			diskp->dk_rbytes += bcount;
-			diskp->dk_rxfer++;
-		} else {
-			diskp->dk_wbytes += bcount;
-			diskp->dk_wxfer++;
-		}
-	}
-}
-
-/*
- * Reset the metrics counters on the given disk.  Note that we cannot
- * reset the busy counter, as it may case a panic in disk_unbusy().
- * We also must avoid playing with the timestamp information, as it
- * may skew any pending transfer results.
- */
-void
-disk_resetstat(struct disk *diskp)
-{
-	int s = splbio(), t;
-
-	diskp->dk_rxfer = 0;
-	diskp->dk_rbytes = 0;
-	diskp->dk_wxfer = 0;
-	diskp->dk_wbytes = 0;
-
-	t = splclock();
-	diskp->dk_attachtime = mono_time;
-	splx(t);
-
-	timerclear(&diskp->dk_time);
-
-	splx(s);
-}
-
-int
-sysctl_hw_disknames(SYSCTLFN_ARGS)
-{
-	char bf[DK_DISKNAMELEN + 1];
-	char *where = oldp;
-	struct disk *diskp;
-	size_t needed, left, slen;
-	int error, first;
-
-	if (newp != NULL)
-		return (EPERM);
-	if (namelen != 0)
-		return (EINVAL);
-
-	first = 1;
-	error = 0;
-	needed = 0;
-	left = *oldlenp;
-
-	simple_lock(&disklist_slock);
-	for (diskp = TAILQ_FIRST(&disklist); diskp != NULL;
-	    diskp = TAILQ_NEXT(diskp, dk_link)) {
-		if (where == NULL)
-			needed += strlen(diskp->dk_name) + 1;
-		else {
-			memset(bf, 0, sizeof(bf));
-			if (first) {
-				strncpy(bf, diskp->dk_name, sizeof(bf));
-				first = 0;
-			} else {
-				bf[0] = ' ';
-				strncpy(bf + 1, diskp->dk_name,
-				    sizeof(bf) - 1);
-			}
-			bf[DK_DISKNAMELEN] = '\0';
-			slen = strlen(bf);
-			if (left < slen + 1)
-				break;
-			/* +1 to copy out the trailing NUL byte */
-			error = copyout(bf, where, slen + 1);
-			if (error)
-				break;
-			where += slen;
-			needed += slen;
-			left -= slen;
-		}
-	}
-	simple_unlock(&disklist_slock);
-	*oldlenp = needed;
-	return (error);
-}
-
-int
-sysctl_hw_diskstats(SYSCTLFN_ARGS)
-{
-	struct disk_sysctl sdisk;
-	struct disk *diskp;
-	char *where = oldp;
-	size_t tocopy, left;
-	int error;
-
-	if (newp != NULL)
-		return (EPERM);
-
-	/*
-	 * The original hw.diskstats call was broken and did not require
-	 * the userland to pass in it's size of struct disk_sysctl.  This
-	 * was fixed after NetBSD 1.6 was released, and any applications
-	 * that do not pass in the size are given an error only, unless
-	 * we care about 1.6 compatibility.
-	 */
-	if (namelen == 0)
-#ifdef COMPAT_16
-		tocopy = offsetof(struct disk_sysctl, dk_rxfer);
-#else
-		return (EINVAL);
-#endif
-	else
-		tocopy = name[0];
-
-	if (where == NULL) {
-		*oldlenp = disk_count * tocopy;
-		return (0);
-	}
-
-	error = 0;
-	left = *oldlenp;
-	memset(&sdisk, 0, sizeof(sdisk));
-	*oldlenp = 0;
-
-	simple_lock(&disklist_slock);
-	TAILQ_FOREACH(diskp, &disklist, dk_link) {
-		if (left < tocopy)
-			break;
-		strncpy(sdisk.dk_name, diskp->dk_name, sizeof(sdisk.dk_name));
-		sdisk.dk_xfer = diskp->dk_rxfer + diskp->dk_wxfer;
-		sdisk.dk_rxfer = diskp->dk_rxfer;
-		sdisk.dk_wxfer = diskp->dk_wxfer;
-		sdisk.dk_seek = diskp->dk_seek;
-		sdisk.dk_bytes = diskp->dk_rbytes + diskp->dk_wbytes;
-		sdisk.dk_rbytes = diskp->dk_rbytes;
-		sdisk.dk_wbytes = diskp->dk_wbytes;
-		sdisk.dk_attachtime_sec = diskp->dk_attachtime.tv_sec;
-		sdisk.dk_attachtime_usec = diskp->dk_attachtime.tv_usec;
-		sdisk.dk_timestamp_sec = diskp->dk_timestamp.tv_sec;
-		sdisk.dk_timestamp_usec = diskp->dk_timestamp.tv_usec;
-		sdisk.dk_time_sec = diskp->dk_time.tv_sec;
-		sdisk.dk_time_usec = diskp->dk_time.tv_usec;
-		sdisk.dk_busy = diskp->dk_busy;
-
-		error = copyout(&sdisk, where, min(tocopy, sizeof(sdisk)));
-		if (error)
-			break;
-		where += tocopy;
-		*oldlenp += tocopy;
-		left -= tocopy;
-	}
-	simple_unlock(&disklist_slock);
-	return (error);
+	iostat_unbusy(diskp->dk_stats, bcount, read);
 }
 
 /*
diff --git a/sys/nfs/nfs_vfsops.c b/sys/nfs/nfs_vfsops.c
index 7d7faac4db40..8e68cde0b0a5 100644
--- a/sys/nfs/nfs_vfsops.c
+++ b/sys/nfs/nfs_vfsops.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: nfs_vfsops.c,v 1.152 2006/02/21 04:32:39 thorpej Exp $	*/
+/*	$NetBSD: nfs_vfsops.c,v 1.153 2006/04/14 13:09:06 blymn Exp $	*/
 
 /*
  * Copyright (c) 1989, 1993, 1995
@@ -35,7 +35,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: nfs_vfsops.c,v 1.152 2006/02/21 04:32:39 thorpej Exp $");
+__KERNEL_RCSID(0, "$NetBSD: nfs_vfsops.c,v 1.153 2006/04/14 13:09:06 blymn Exp $");
 
 #if defined(_KERNEL_OPT)
 #include "opt_compat_netbsd.h"
@@ -77,6 +77,12 @@ __KERNEL_RCSID(0, "$NetBSD: nfs_vfsops.c,v 1.152 2006/02/21 04:32:39 thorpej Exp
 extern struct nfsstats nfsstats;
 extern int nfs_ticks;
 
+/*
+ * keep a count of the nfs mounts to generate ficticious drive names
+ * for the per drive stats.
+ */
+unsigned int nfs_mount_count = 0;
+
 MALLOC_DEFINE(M_NFSMNT, "NFS mount", "NFS mount structure");
 
 /*
@@ -800,6 +806,13 @@ mountnfs(argp, mp, nam, pth, hst, vpp, l)
 	nmp->nm_vnode = *vpp;
 	VOP_UNLOCK(*vpp, 0);
 
+	nmp->nm_stats = iostat_alloc(IOSTAT_NFS);
+	nmp->nm_stats->parent = nmp;
+	  /* generate a ficticious drive name for the nfs mount */
+	MALLOC(nmp->nm_stats->name, char *, IOSTATNAMELEN, M_NFSMNT, M_WAITOK);
+	snprintf(nmp->nm_stats->name, IOSTATNAMELEN, "nfs%u", nfs_mount_count);
+	nfs_mount_count++;
+
 	return (0);
 bad:
 	nfs_disconnect(nmp);
@@ -868,6 +881,14 @@ nfs_unmount(mp, mntflags, l)
 	 */
 	nmp->nm_iflag |= NFSMNT_DISMNT;
 
+	/*
+	 * Clean up the stats... note that we carefully avoid decrementing
+	 * nfs_mount_count here for good reason - we may not be unmounting
+	 * the last thing mounted.
+	 */
+	FREE(nmp->nm_stats->name, M_NFSMNT);
+	iostat_free(nmp->nm_stats);
+
 	/*
 	 * There are two reference counts to get rid of here
 	 * (see comment in mountnfs()).
diff --git a/sys/nfs/nfs_vnops.c b/sys/nfs/nfs_vnops.c
index 1a2bebb85124..fb71d60e9374 100644
--- a/sys/nfs/nfs_vnops.c
+++ b/sys/nfs/nfs_vnops.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: nfs_vnops.c,v 1.231 2006/03/01 12:38:32 yamt Exp $	*/
+/*	$NetBSD: nfs_vnops.c,v 1.232 2006/04/14 13:09:06 blymn Exp $	*/
 
 /*
  * Copyright (c) 1989, 1993
@@ -39,7 +39,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: nfs_vnops.c,v 1.231 2006/03/01 12:38:32 yamt Exp $");
+__KERNEL_RCSID(0, "$NetBSD: nfs_vnops.c,v 1.232 2006/04/14 13:09:06 blymn Exp $");
 
 #include "opt_inet.h"
 #include "opt_nfs.h"
@@ -53,6 +53,7 @@ __KERNEL_RCSID(0, "$NetBSD: nfs_vnops.c,v 1.231 2006/03/01 12:38:32 yamt Exp $")
 #include <sys/proc.h>
 #include <sys/mount.h>
 #include <sys/buf.h>
+#include <sys/disk.h>
 #include <sys/malloc.h>
 #include <sys/mbuf.h>
 #include <sys/namei.h>
@@ -1240,7 +1241,7 @@ nfs_readrpc(vp, uiop)
 	caddr_t bpos, dpos, cp2;
 	struct mbuf *mreq, *mrep, *md, *mb;
 	struct nfsmount *nmp;
-	int error = 0, len, retlen, tsiz, eof;
+	int error = 0, len, retlen, tsiz, eof, byte_count;
 	const int v3 = NFS_ISV3(vp);
 	struct nfsnode *np = VTONFS(vp);
 #ifndef NFS_V2_ONLY
@@ -1254,6 +1255,8 @@ nfs_readrpc(vp, uiop)
 	tsiz = uiop->uio_resid;
 	if (uiop->uio_offset + tsiz > nmp->nm_maxfilesize)
 		return (EFBIG);
+	iostat_busy(nmp->nm_stats);
+	byte_count = 0; /* count bytes actually transferred */
 	while (tsiz > 0) {
 		nfsstats.rpccnt[NFSPROC_READ]++;
 		len = (tsiz > nmp->nm_rsize) ? nmp->nm_rsize : tsiz;
@@ -1288,6 +1291,7 @@ nfs_readrpc(vp, uiop)
 		nfsm_mtouio(uiop, retlen);
 		m_freem(mrep);
 		tsiz -= retlen;
+		byte_count += retlen;
 #ifndef NFS_V2_ONLY
 		if (v3) {
 			if (eof || retlen == 0)
@@ -1298,6 +1302,7 @@ nfs_readrpc(vp, uiop)
 			tsiz = 0;
 	}
 nfsmout:
+	iostat_unbusy(nmp->nm_stats, byte_count, 1);
 	return (error);
 }
 
@@ -1347,7 +1352,7 @@ nfs_writerpc(vp, uiop, iomode, pageprotected, stalewriteverfp)
 	int committed = NFSV3WRITE_FILESYNC;
 	struct nfsnode *np = VTONFS(vp);
 	struct nfs_writerpc_context ctx;
-	int s;
+	int s, byte_count;
 	struct lwp *l = NULL;
 	size_t origresid;
 #ifndef NFS_V2_ONLY
@@ -1376,6 +1381,8 @@ nfs_writerpc(vp, uiop, iomode, pageprotected, stalewriteverfp)
 retry:
 	origresid = uiop->uio_resid;
 	KASSERT(origresid == uiop->uio_iov->iov_len);
+	iostat_busy(nmp->nm_stats);
+	byte_count = 0; /* count of bytes actually written */
 	while (tsiz > 0) {
 		uint32_t datalen; /* data bytes need to be allocated in mbuf */
 		uint32_t backup;
@@ -1508,6 +1515,7 @@ retry:
 		if (error)
 			break;
 		tsiz -= len;
+		byte_count += len;
 		if (stalewriteverf) {
 			*stalewriteverfp = TRUE;
 			stalewriteverf = FALSE;
@@ -1528,6 +1536,7 @@ retry:
 		}
 	}
 nfsmout:
+	iostat_unbusy(nmp->nm_stats, byte_count, 0);
 	if (pageprotected) {
 		/*
 		 * wait until mbufs go away.
diff --git a/sys/nfs/nfsmount.h b/sys/nfs/nfsmount.h
index ee6c580c4082..72ecb1da80f9 100644
--- a/sys/nfs/nfsmount.h
+++ b/sys/nfs/nfsmount.h
@@ -1,4 +1,4 @@
-/*	$NetBSD: nfsmount.h,v 1.37 2005/12/11 12:25:17 christos Exp $	*/
+/*	$NetBSD: nfsmount.h,v 1.38 2006/04/14 13:09:07 blymn Exp $	*/
 
 /*
  * Copyright (c) 1989, 1993
@@ -37,6 +37,9 @@
 
 #ifndef _NFS_NFSMOUNT_H_
 #define _NFS_NFSMOUNT_H_
+#ifdef _KERNEL
+#include <sys/disk.h>
+#endif
 
 /*
  * Arguments to mount NFS
@@ -167,6 +170,7 @@ struct	nfsmount {
 	int	nm_iflag;		/* internal flags */
 	int	nm_waiters;		/* number of waiting listeners.. */
 	long	nm_wcckludgetime;	/* see nfs_check_wccdata() */
+	struct io_stats *nm_stats;	/* per nfs mount statistics */
 };
 
 /*
diff --git a/sys/sys/Makefile b/sys/sys/Makefile
index e57a2dd87e80..052627dd072c 100644
--- a/sys/sys/Makefile
+++ b/sys/sys/Makefile
@@ -1,4 +1,4 @@
-#	$NetBSD: Makefile,v 1.82 2006/02/11 17:36:41 jmmv Exp $
+#	$NetBSD: Makefile,v 1.83 2006/04/14 13:09:07 blymn Exp $
 
 INCSDIR= /usr/include/sys
 
@@ -12,7 +12,7 @@ INCS=	acct.h agpio.h ansi.h ataio.h audioio.h \
 	exec_coff.h exec_ecoff.h exec_elf.h exec_script.h extattr.h extent.h \
 	fcntl.h fd_set.h fdio.h featuretest.h file.h filedesc.h filio.h \
 	float_ieee754.h fstypes.h gmon.h gpio.h hash.h \
-	ieee754.h inttypes.h ioccom.h ioctl.h ioctl_compat.h ipc.h \
+	ieee754.h inttypes.h ioccom.h ioctl.h ioctl_compat.h iostat.h ipc.h \
 	joystick.h \
 	kcore.h kgdb.h ksem.h ksyms.h ktrace.h \
 	lkm.h localedef.h lock.h lockf.h lwp.h \
diff --git a/sys/sys/disk.h b/sys/sys/disk.h
index 72802c78765a..e4114a7c3383 100644
--- a/sys/sys/disk.h
+++ b/sys/sys/disk.h
@@ -1,4 +1,4 @@
-/*	$NetBSD: disk.h,v 1.33 2005/12/26 18:41:36 perry Exp $	*/
+/*	$NetBSD: disk.h,v 1.34 2006/04/14 13:09:07 blymn Exp $	*/
 
 /*-
  * Copyright (c) 1996, 1997, 2004 The NetBSD Foundation, Inc.
@@ -90,6 +90,7 @@
 #include <sys/time.h>
 #include <sys/queue.h>
 #include <sys/lock.h>
+#include <sys/iostat.h>
 
 struct buf;
 struct disk;
@@ -209,15 +210,7 @@ struct disk {
 	 * Metrics data; note that some metrics may have no meaning
 	 * on certain types of disks.
 	 */
-	int		dk_busy;	/* busy counter */
-	uint64_t	dk_rxfer;	/* total number of read transfers */
-	uint64_t	dk_wxfer;	/* total number of write transfers */
-	uint64_t	dk_seek;	/* total independent seek operations */
-	uint64_t	dk_rbytes;	/* total bytes read */
-	uint64_t	dk_wbytes;	/* total bytes written */
-	struct timeval	dk_attachtime;	/* time disk was attached */
-	struct timeval	dk_timestamp;	/* timestamp of last unbusy */
-	struct timeval	dk_time;	/* total time spent busy */
+	struct io_stats	*dk_stats;
 
 	struct	dkdriver *dk_driver;	/* pointer to driver */
 
@@ -243,29 +236,6 @@ struct disk {
 	struct cpu_disklabel *dk_cpulabel;
 };
 
-#define	DK_DISKNAMELEN	16
-
-/* The following structure is 64-bit alignment safe */
-struct disk_sysctl {
-	char		dk_name[DK_DISKNAMELEN];
-	int32_t		dk_busy;
-	int32_t		pad;
-	uint64_t	dk_xfer;
-	uint64_t	dk_seek;
-	uint64_t	dk_bytes;
-	uint32_t	dk_attachtime_sec;
-	uint32_t	dk_attachtime_usec;
-	uint32_t	dk_timestamp_sec;
-	uint32_t	dk_timestamp_usec;
-	uint32_t	dk_time_sec;
-	uint32_t	dk_time_usec;
-	/* New separate read/write stats */
-	uint64_t	dk_rxfer;
-	uint64_t	dk_rbytes;
-	uint64_t	dk_wxfer;
-	uint64_t	dk_wbytes;
-};
-
 struct dkdriver {
 	void	(*d_strategy)(struct buf *);
 	void	(*d_minphys)(struct buf *);
@@ -287,11 +257,6 @@ struct dkdriver {
 #define	DK_OPEN		4		/* label read, drive open */
 #define	DK_OPENRAW	5		/* open without label */
 
-/*
- * disklist_head is defined here so that user-land has access to it.
- */
-TAILQ_HEAD(disklist_head, disk);	/* the disklist is a TAILQ */
-
 /*
  * Bad sector lists per fixed disk
  */
@@ -328,10 +293,9 @@ void	disk_detach(struct disk *);
 void	pseudo_disk_init(struct disk *);
 void	pseudo_disk_attach(struct disk *);
 void	pseudo_disk_detach(struct disk *);
-void	disk_busy(struct disk *);
-void	disk_unbusy(struct disk *, long, int);
-void	disk_resetstat(struct disk *);
-struct	disk *disk_find(char *);
+void    disk_busy(struct disk *);
+void    disk_unbusy(struct disk *, long, int);
+struct  disk *disk_find(char *);
 
 int	dkwedge_add(struct dkwedge_info *);
 int	dkwedge_del(struct dkwedge_info *);
diff --git a/sys/sys/iostat.h b/sys/sys/iostat.h
new file mode 100644
index 000000000000..1a789c5a3c2b
--- /dev/null
+++ b/sys/sys/iostat.h
@@ -0,0 +1,115 @@
+/*	$NetBSD: iostat.h,v 1.1 2006/04/14 13:09:07 blymn Exp $	*/
+
+/*-
+ * Copyright (c) 1996, 1997, 2004 The NetBSD Foundation, Inc.
+ * All rights reserved.
+ *
+ * This code is derived from software contributed to The NetBSD Foundation
+ * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility,
+ * NASA Ames Research Center.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the NetBSD
+ *	Foundation, Inc. and its contributors.
+ * 4. Neither the name of The NetBSD Foundation nor the names of its
+ *    contributors may be used to endorse or promote products derived
+ *    from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
+ * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+ * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
+ * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef _SYS_IOSTAT_H_
+#define _SYS_IOSTAT_H_
+
+/*
+ * Disk device structures.
+ */
+
+#include <sys/time.h>
+#include <sys/queue.h>
+#include <sys/lock.h>
+
+#define	IOSTATNAMELEN	16
+
+/* types of drives we can have */
+#define IOSTAT_DISK	0
+#define IOSTAT_TAPE	1
+#define IOSTAT_NFS	2
+
+/* The following structure is 64-bit alignment safe */
+struct io_sysctl {
+	char		name[IOSTATNAMELEN];
+	int32_t		busy;
+	int32_t		type;
+	u_int64_t	xfer;
+	u_int64_t	seek;
+	u_int64_t	bytes;
+	u_int32_t	attachtime_sec;
+	u_int32_t	attachtime_usec;
+	u_int32_t	timestamp_sec;
+	u_int32_t	timestamp_usec;
+	u_int32_t	time_sec;
+	u_int32_t	time_usec;
+	/* New separate read/write stats */
+	u_int64_t	rxfer;
+	u_int64_t	rbytes;
+	u_int64_t	wxfer;
+	u_int64_t	wbytes;
+};
+
+/*
+ * Structure for keeping the in-kernel drive stats - these are linked
+ * together in drivelist.
+ */
+
+struct io_stats
+{
+	char		*name;  /* device name */
+	void		*parent; /* pointer to what we are attached to */
+	int		type;   /* type of device the state belong to */
+	int		busy;	/* busy counter */
+	u_int64_t	rxfer;	/* total number of read transfers */
+	u_int64_t	wxfer;	/* total number of write transfers */
+	u_int64_t	seek;	/* total independent seek operations */
+	u_int64_t	rbytes;	/* total bytes read */
+	u_int64_t	wbytes;	/* total bytes written */
+	struct timeval	attachtime;	/* time disk was attached */
+	struct timeval	timestamp;	/* timestamp of last unbusy */
+	struct timeval	time;	/* total time spent busy */
+	TAILQ_ENTRY(io_stats) link;
+};
+
+/*
+ * drivelist_head is defined here so that user-land has access to it.
+ */
+TAILQ_HEAD(iostatlist_head, io_stats);	/* the iostatlist is a TAILQ */
+
+#ifdef _KERNEL
+void	iostat_busy(struct io_stats *);
+void	iostat_unbusy(struct io_stats *, long, int);
+struct	io_stats *iostat_find(char *);
+struct  io_stats *iostat_alloc(int32_t);
+void	iostat_free(struct io_stats *);
+void	iostat_seek(struct io_stats *);
+#endif
+
+#endif /* _SYS_IOSTAT_H_ */
diff --git a/sys/sys/sysctl.h b/sys/sys/sysctl.h
index 46fb6b6f7205..1a094ccc77cb 100644
--- a/sys/sys/sysctl.h
+++ b/sys/sys/sysctl.h
@@ -1,4 +1,4 @@
-/*	$NetBSD: sysctl.h,v 1.153 2006/03/17 08:50:36 kleink Exp $	*/
+/*	$NetBSD: sysctl.h,v 1.154 2006/04/14 13:09:07 blymn Exp $	*/
 
 /*
  * Copyright (c) 1989, 1993
@@ -714,15 +714,14 @@ struct kinfo_file {
 #define	HW_USERMEM	 6		/* int: non-kernel memory (bytes) */
 #define	HW_PAGESIZE	 7		/* int: software page size */
 #define	HW_DISKNAMES	 8		/* string: disk drive names */
-#define	HW_DISKSTATS	 9		/* struct: diskstats[] */
+#define	HW_IOSTATS	 9		/* struct: iostats[] */
 #define	HW_MACHINE_ARCH	10		/* string: machine architecture */
 #define	HW_ALIGNBYTES	11		/* int: ALIGNBYTES for the kernel */
 #define	HW_CNMAGIC	12		/* string: console magic sequence(s) */
 #define	HW_PHYSMEM64	13		/* quad: total memory (bytes) */
 #define	HW_USERMEM64	14		/* quad: non-kernel memory (bytes) */
-#define	HW_TAPENAMES	15		/* string: tape drive names */
-#define	HW_TAPESTATS	16		/* struct: tapestats[] */
-#define	HW_MAXID	16		/* number of valid hw ids */
+#define	HW_IOSTATNAMES	15		/* string: iostat names */
+#define	HW_MAXID	15		/* number of valid hw ids */
 
 #define	CTL_HW_NAMES { \
 	{ 0, 0 }, \
@@ -733,8 +732,8 @@ struct kinfo_file {
 	{ "physmem", CTLTYPE_INT }, \
 	{ "usermem", CTLTYPE_INT }, \
 	{ "pagesize", CTLTYPE_INT }, \
-	{ "disknames", CTLTYPE_STRING }, \
-	{ "diskstats", CTLTYPE_STRUCT }, \
+	{ "drivenames", CTLTYPE_STRING }, \
+	{ "drivestats", CTLTYPE_STRUCT }, \
 	{ "machine_arch", CTLTYPE_STRING }, \
 	{ "alignbytes", CTLTYPE_INT }, \
 	{ "cnmagic", CTLTYPE_STRING }, \
@@ -1085,8 +1084,6 @@ int	old_sysctl(int *, u_int, void *, size_t *, void *, size_t, struct lwp *);
  * these helpers are in other files (XXX so should the nodes be) or
  * are used by more than one node
  */
-int	sysctl_hw_disknames(SYSCTLFN_PROTO);
-int	sysctl_hw_diskstats(SYSCTLFN_PROTO);
 int	sysctl_hw_tapenames(SYSCTLFN_PROTO);
 int	sysctl_hw_tapestats(SYSCTLFN_PROTO);
 int	sysctl_kern_vnode(SYSCTLFN_PROTO);