Index: head/sys/cam/ata/ata_da.c
===================================================================
--- head/sys/cam/ata/ata_da.c
+++ head/sys/cam/ata/ata_da.c
@@ -3420,6 +3420,8 @@
 	softc->disk->d_fwheads = softc->params.heads;
 	ata_disk_firmware_geom_adjust(softc->disk);
 	softc->disk->d_rotation_rate = cgd->ident_data.media_rotation_rate;
+	snprintf(softc->disk->d_attachment, sizeof(softc->disk->d_attachment),
+	    "%s%d", softc->cpi.dev_name, softc->cpi.unit_number);
 }
 
 static void
Index: head/sys/cam/mmc/mmc_da.c
===================================================================
--- head/sys/cam/mmc/mmc_da.c
+++ head/sys/cam/mmc/mmc_da.c
@@ -1532,6 +1532,8 @@
 	part->disk->d_hba_device = cpi.hba_device;
 	part->disk->d_hba_subvendor = cpi.hba_subvendor;
 	part->disk->d_hba_subdevice = cpi.hba_subdevice;
+	snprintf(part->disk->d_attachment, sizeof(part->disk->d_attachment),
+	    "%s%d", cpi.dev_name, cpi.unit_number);
 
 	part->disk->d_sectorsize = mmc_get_sector_size(periph);
 	part->disk->d_mediasize = media_size;
Index: head/sys/cam/nvme/nvme_da.c
===================================================================
--- head/sys/cam/nvme/nvme_da.c
+++ head/sys/cam/nvme/nvme_da.c
@@ -815,6 +815,8 @@
 	disk->d_hba_device = cpi.hba_device;
 	disk->d_hba_subvendor = cpi.hba_subvendor;
 	disk->d_hba_subdevice = cpi.hba_subdevice;
+	snprintf(disk->d_attachment, sizeof(disk->d_attachment),
+	    "%s%d", cpi.dev_name, cpi.unit_number);
 	disk->d_stripesize = disk->d_sectorsize;
 	disk->d_stripeoffset = 0;
 	disk->d_devstat = devstat_new_entry(periph->periph_name,
Index: head/sys/cam/scsi/scsi_cd.c
===================================================================
--- head/sys/cam/scsi/scsi_cd.c
+++ head/sys/cam/scsi/scsi_cd.c
@@ -702,6 +702,8 @@
 	softc->disk->d_hba_device = cpi.hba_device;
 	softc->disk->d_hba_subvendor = cpi.hba_subvendor;
 	softc->disk->d_hba_subdevice = cpi.hba_subdevice;
+	snprintf(softc->disk->d_attachment, sizeof(softc->disk->d_attachment),
+	    "%s%d", cpi.dev_name, cpi.unit_number);
 
 	/*
 	 * Acquire a reference to the periph before we register with GEOM.
Index: head/sys/cam/scsi/scsi_da.c
===================================================================
--- head/sys/cam/scsi/scsi_da.c
+++ head/sys/cam/scsi/scsi_da.c
@@ -2875,6 +2875,8 @@
 	softc->disk->d_hba_device = cpi.hba_device;
 	softc->disk->d_hba_subvendor = cpi.hba_subvendor;
 	softc->disk->d_hba_subdevice = cpi.hba_subdevice;
+	snprintf(softc->disk->d_attachment, sizeof(softc->disk->d_attachment),
+	    "%s%d", cpi.dev_name, cpi.unit_number);
 
 	/*
 	 * Acquire a reference to the periph before we register with GEOM.
Index: head/sys/geom/geom_disk.h
===================================================================
--- head/sys/geom/geom_disk.h
+++ head/sys/geom/geom_disk.h
@@ -118,6 +118,7 @@
 	uint16_t		d_hba_subvendor;
 	uint16_t		d_hba_subdevice;
 	uint16_t		d_rotation_rate;
+	char			d_attachment[DISK_IDENT_SIZE];
 
 	/* Fields private to the driver */
 	void			*d_drv1;
Index: head/sys/geom/geom_disk.c
===================================================================
--- head/sys/geom/geom_disk.c
+++ head/sys/geom/geom_disk.c
@@ -528,7 +528,10 @@
 		else if (g_handleattr_uint16_t(bp, "GEOM::rotation_rate",
 		    dp->d_rotation_rate))
 			break;
-		else 
+		else if (g_handleattr_str(bp, "GEOM::attachment",
+		    dp->d_attachment))
+			break;
+		else
 			error = ENOIOCTL;
 		break;
 	case BIO_FLUSH:
Index: head/usr.sbin/diskinfo/diskinfo.c
===================================================================
--- head/usr.sbin/diskinfo/diskinfo.c
+++ head/usr.sbin/diskinfo/diskinfo.c
@@ -251,6 +251,10 @@
 				printf("\t%-12s\t# Disk descr.\n", arg.value.str);
 			if (ioctl(fd, DIOCGIDENT, ident) == 0)
 				printf("\t%-12s\t# Disk ident.\n", ident);
+			strlcpy(arg.name, "GEOM::attachment", sizeof(arg.name));
+			arg.len = sizeof(arg.value.str);
+			if (ioctl(fd, DIOCGATTR, &arg) == 0)
+				printf("\t%-12s\t# Attachment\n", arg.value.str);
 			if (ioctl(fd, DIOCGPHYSPATH, physpath) == 0)
 				printf("\t%-12s\t# Physical path\n", physpath);
 			printf("\t%-12s\t# TRIM/UNMAP support\n",