Index: sd.c
===================================================================
RCS file: /cvsroot/src/sys/dev/scsipi/sd.c,v
retrieving revision 1.338
diff -p -u -r1.338 sd.c
--- sd.c	11 Feb 2025 15:02:42 -0000	1.338
+++ sd.c	19 Feb 2025 16:04:05 -0000
@@ -1199,10 +1199,13 @@ sd_dumpblocks(device_t dev, void *va, da
 	struct dk_softc *dksc = &sd->sc_dksc;
 	struct disk_geom *dg = &dksc->sc_dkdev.dk_geom;
 	struct scsipi_rw_10 cmd;	/* write command */
+	struct scsipi_rw_16 cmd16;	/* write command */
+	struct scsipi_generic *cmdp;
 	struct scsipi_xfer *xs;		/* ... convenience */
 	struct scsipi_periph *periph;
 	struct scsipi_channel *chan;
 	size_t sectorsize;
+	int cmdlen;
 
 	periph = sd->sc_periph;
 	chan = periph->periph_channel;
@@ -1215,10 +1218,22 @@ sd_dumpblocks(device_t dev, void *va, da
 	/*
 	 *  Fill out the scsi command
 	 */
-	memset(&cmd, 0, sizeof(cmd));
-	cmd.opcode = WRITE_10;
-	_lto4b(blkno, cmd.addr);
-	_lto2b(nblk, cmd.length);
+	if ((blkno & 0xffffffff) == blkno) {
+		memset(&cmd, 0, sizeof(cmd));
+		cmd.opcode = WRITE_10;
+		_lto4b(blkno, cmd.addr);
+		_lto2b(nblk, cmd.length);
+		cmdlen = sizeof(cmd);
+		cmdp = (struct scsipi_generic *)&cmd;
+	} else {
+		memset(&cmd16, 0, sizeof(cmd16));
+		cmd16.opcode = WRITE_16;
+		_lto8b(blkno, cmd16.addr);
+		_lto4b(nblk, cmd16.length);
+		cmdlen = sizeof(cmd16);
+		cmdp = (struct scsipi_generic *)&cmd16;
+	}
+
 	/*
 	 * Fill out the scsipi_xfer structure
 	 *    Note: we cannot sleep as we may be an interrupt
@@ -1232,8 +1247,8 @@ sd_dumpblocks(device_t dev, void *va, da
 	xs->xs_periph = periph;
 	xs->xs_retries = SDRETRIES;
 	xs->timeout = 10000;	/* 10000 millisecs for a disk ! */
-	xs->cmd = (struct scsipi_generic *)&cmd;
-	xs->cmdlen = sizeof(cmd);
+	xs->cmd = cmdp;
+	xs->cmdlen = cmdlen;
 	xs->resid = nblk * sectorsize;
 	xs->error = XS_NOERROR;
 	xs->bp = 0;