diff --git a/tests/zfs-tests/include/blkdev.shlib b/tests/zfs-tests/include/blkdev.shlib
index 5a750bf1b1..2269131a45 100644
--- a/tests/zfs-tests/include/blkdev.shlib
+++ b/tests/zfs-tests/include/blkdev.shlib
@@ -89,8 +89,8 @@ function block_device_wait
 #
 function is_physical_device #device
 {
-	typeset device=${1#$DEV_DSKDIR}
-	device=${device#$DEV_RDSKDIR}
+	typeset device=${1#$DEV_DSKDIR/}
+	device=${device#$DEV_RDSKDIR/}
 
 	if is_linux; then
 		is_disk_device "$DEV_DSKDIR/$device" && \
@@ -216,9 +216,6 @@ function set_slice_prefix
 			fi
 			(( i = i + 1))
 		done
-	elif is_freebsd; then
-		export SLICE_PREFIX="p"
-		return 0
 	fi
 }
 
diff --git a/tests/zfs-tests/include/default.cfg.in b/tests/zfs-tests/include/default.cfg.in
index 1281176cba..741c0d3b2c 100644
--- a/tests/zfs-tests/include/default.cfg.in
+++ b/tests/zfs-tests/include/default.cfg.in
@@ -173,6 +173,7 @@ if is_linux; then
 
 	ZVOL_DEVDIR="/dev/zvol"
 	ZVOL_RDEVDIR="/dev/zvol"
+	DEV_DSKDIR="/dev"
 	DEV_RDSKDIR="/dev"
 	DEV_MPATHDIR="/dev/mapper"
 
@@ -182,8 +183,8 @@ if is_linux; then
 	VDEVID_CONF="$ZEDLET_DIR/vdev_id.conf"
 	VDEVID_CONF_ETC="/etc/zfs/vdev_id.conf"
 
-
 	NEWFS_DEFAULT_FS="ext2"
+	SLICE_PREFIX=""
 elif is_freebsd; then
 	unpack_opts="xv"
 	pack_opts="cf"
@@ -198,6 +199,7 @@ elif is_freebsd; then
 	DEV_MPATHDIR="/dev/multipath"
 
 	NEWFS_DEFAULT_FS="ufs"
+	SLICE_PREFIX="p"
 else
 	unpack_opts="xv"
 	pack_opts="cf"
@@ -211,8 +213,9 @@ else
 	DEV_RDSKDIR="/dev/rdsk"
 
 	NEWFS_DEFAULT_FS="ufs"
+	SLICE_PREFIX="s"
 fi
 export unpack_opts pack_opts verbose unpack_preserve pack_preserve \
        ZVOL_DEVDIR ZVOL_RDEVDIR DEV_DSKDIR DEV_RDSKDIR DEV_MPATHDIR \
        ZEDLET_DIR ZED_LOG ZED_DEBUG_LOG VDEVID_CONF VDEVID_CONF_ETC \
-       NEWFS_DEFAULT_FS
+       NEWFS_DEFAULT_FS SLICE_PREFIX
diff --git a/tests/zfs-tests/include/libtest.shlib b/tests/zfs-tests/include/libtest.shlib
index 4ad3ee9bf6..ac9ff61836 100644
--- a/tests/zfs-tests/include/libtest.shlib
+++ b/tests/zfs-tests/include/libtest.shlib
@@ -914,14 +914,15 @@ function set_partition
 	typeset -i slicenum=$1
 	typeset start=$2
 	typeset size=$3
-	typeset disk=$4
+	typeset disk=${4#$DEV_DSKDIR/}
+	disk=${disk#$DEV_RDSKDIR/}
 
 	case "$(uname)" in
 	Linux)
 		if [[ -z $size || -z $disk ]]; then
 			log_fail "The size or disk name is unspecified."
 		fi
-		[[ -n $DEV_DSKDIR ]] && disk=$DEV_DSKDIR/$disk
+		disk=$DEV_DSKDIR/$disk
 		typeset size_mb=${size%%[mMgG]}
 
 		size_mb=${size_mb%%[mMgG][bB]}
@@ -969,7 +970,7 @@ function set_partition
 		if [[ -z $size || -z $disk ]]; then
 			log_fail "The size or disk name is unspecified."
 		fi
-		[[ -n $DEV_DSKDIR ]] && disk=$DEV_DSKDIR/$disk
+		disk=$DEV_DSKDIR/$disk
 
 		if [[ $slicenum -eq 0 ]] || ! gpart show $disk >/dev/null 2>&1; then
 			gpart destroy -F $disk >/dev/null 2>&1
diff --git a/tests/zfs-tests/tests/functional/cli_root/zpool_add/zpool_add.cfg b/tests/zfs-tests/tests/functional/cli_root/zpool_add/zpool_add.cfg
index b9e687c2b4..e1c7d47cea 100644
--- a/tests/zfs-tests/tests/functional/cli_root/zpool_add/zpool_add.cfg
+++ b/tests/zfs-tests/tests/functional/cli_root/zpool_add/zpool_add.cfg
@@ -73,8 +73,6 @@ if is_linux || is_freebsd; then
 	export SLICE5=6
 	export SLICE6=7
 else
-	export DEV_DSKDIR="/dev"
-	export SLICE_PREFIX="s"
 	export SLICE0=0
 	export SLICE1=1
 	export SLICE3=3
diff --git a/tests/zfs-tests/tests/functional/cli_root/zpool_create/zpool_create.cfg b/tests/zfs-tests/tests/functional/cli_root/zpool_create/zpool_create.cfg
index d58cece040..d3ccc47e73 100644
--- a/tests/zfs-tests/tests/functional/cli_root/zpool_create/zpool_create.cfg
+++ b/tests/zfs-tests/tests/functional/cli_root/zpool_create/zpool_create.cfg
@@ -78,7 +78,6 @@ if is_linux; then
 		delete_partitions
 	fi
 else
-	export SLICE_PREFIX="s"
 	export SLICE0=0
 	export SLICE1=1
 	export SLICE2=2
diff --git a/tests/zfs-tests/tests/functional/cli_root/zpool_destroy/zpool_destroy.cfg b/tests/zfs-tests/tests/functional/cli_root/zpool_destroy/zpool_destroy.cfg
index 65b43da2da..9349e5ff63 100644
--- a/tests/zfs-tests/tests/functional/cli_root/zpool_destroy/zpool_destroy.cfg
+++ b/tests/zfs-tests/tests/functional/cli_root/zpool_destroy/zpool_destroy.cfg
@@ -38,7 +38,6 @@ if is_linux; then
 	export SLICE0=1
 	export SLICE1=2
 else
-	export SLICE_PREFIX="s"
 	export SLICE0=0
 	export SLICE1=1
 
diff --git a/tests/zfs-tests/tests/functional/cli_root/zpool_remove/zpool_remove.cfg b/tests/zfs-tests/tests/functional/cli_root/zpool_remove/zpool_remove.cfg
index 7def918e8d..bf4b3e3d0b 100644
--- a/tests/zfs-tests/tests/functional/cli_root/zpool_remove/zpool_remove.cfg
+++ b/tests/zfs-tests/tests/functional/cli_root/zpool_remove/zpool_remove.cfg
@@ -45,7 +45,6 @@ if is_linux; then
 	export SLICE6=7
 	export SLICE7=8
 else
-	export SLICE_PREFIX="s"
 	export SLICE0=0
 	export SLICE1=1
 	export SLICE2=2
diff --git a/tests/zfs-tests/tests/functional/cli_root/zpool_reopen/zpool_reopen.cfg b/tests/zfs-tests/tests/functional/cli_root/zpool_reopen/zpool_reopen.cfg
index 3d6a291e06..7451ffd8c5 100644
--- a/tests/zfs-tests/tests/functional/cli_root/zpool_reopen/zpool_reopen.cfg
+++ b/tests/zfs-tests/tests/functional/cli_root/zpool_reopen/zpool_reopen.cfg
@@ -40,6 +40,4 @@ if is_linux; then
 	devs_id[1]=$(get_persistent_disk_name $DISK2)
 	devs_id[2]=$(get_persistent_disk_name $DISK3)
 	export devs_id
-else
-	DEV_DSKDIR="/dev"
 fi
diff --git a/tests/zfs-tests/tests/functional/fault/fault.cfg b/tests/zfs-tests/tests/functional/fault/fault.cfg
index 25601a71a3..839330ed47 100644
--- a/tests/zfs-tests/tests/functional/fault/fault.cfg
+++ b/tests/zfs-tests/tests/functional/fault/fault.cfg
@@ -47,8 +47,6 @@ if is_linux; then
 	devs_id[1]=$(get_persistent_disk_name $DISK2)
 	devs_id[2]=$(get_persistent_disk_name $DISK3)
 	export devs_id
-else
-	DEV_DSKDIR="/dev"
 fi
 
 export VDEV_FILES="$TEST_BASE_DIR/file-1 $TEST_BASE_DIR/file-2 \
diff --git a/tests/zfs-tests/tests/functional/inuse/inuse.cfg b/tests/zfs-tests/tests/functional/inuse/inuse.cfg
index bbc32f1f10..70b22b4b7a 100644
--- a/tests/zfs-tests/tests/functional/inuse/inuse.cfg
+++ b/tests/zfs-tests/tests/functional/inuse/inuse.cfg
@@ -38,7 +38,6 @@ if is_linux; then
 	export SLICE0=1
 	export SLICE1=2
 else
-	export SLICE_PREFIX="s"
 	export SLICE0=0
 	export SLICE1=1
 fi
diff --git a/tests/zfs-tests/tests/functional/migration/migration.cfg b/tests/zfs-tests/tests/functional/migration/migration.cfg
index 7d86436709..12a5a7799b 100644
--- a/tests/zfs-tests/tests/functional/migration/migration.cfg
+++ b/tests/zfs-tests/tests/functional/migration/migration.cfg
@@ -60,7 +60,6 @@ case "${#disk_array[*]}" in
 			log_fail "$ZFS_DISK not supported for partitioning."
 		fi
 	else
-		export DEV_DSKDIR="/dev"
 		ZFSSIDE_DISK=${SINGLE_DISK}s0
 		NONZFSSIDE_DISK=${SINGLE_DISK}s1
 	fi
@@ -93,7 +92,6 @@ case "${#disk_array[*]}" in
 			log_fail "$NONZFS_DISK not supported for partitioning."
 		fi
 	else
-		export DEV_DSKDIR="/dev"
 		ZFSSIDE_DISK=${ZFS_DISK}s0
 		NONZFSSIDE_DISK=${NONZFS_DISK}s0
 	fi
diff --git a/tests/zfs-tests/tests/functional/write_dirs/write_dirs.cfg b/tests/zfs-tests/tests/functional/write_dirs/write_dirs.cfg
index 400d5bcb1a..356e454a5d 100644
--- a/tests/zfs-tests/tests/functional/write_dirs/write_dirs.cfg
+++ b/tests/zfs-tests/tests/functional/write_dirs/write_dirs.cfg
@@ -41,7 +41,5 @@ if is_linux; then
 	set_device_dir
 	export SLICE=1
 else
-	DEV_DSKDIR="/dev"
-	export SLICE_PREFIX="s"
 	export SLICE=0
 fi
diff --git a/tests/zfs-tests/tests/functional/zvol/zvol_ENOSPC/zvol_ENOSPC.cfg b/tests/zfs-tests/tests/functional/zvol/zvol_ENOSPC/zvol_ENOSPC.cfg
index 84986b832d..8a99225ba9 100644
--- a/tests/zfs-tests/tests/functional/zvol/zvol_ENOSPC/zvol_ENOSPC.cfg
+++ b/tests/zfs-tests/tests/functional/zvol/zvol_ENOSPC/zvol_ENOSPC.cfg
@@ -32,17 +32,10 @@
 
 verify_runnable "global"
 
-#export SIZE="1gb"
 export DISK_ARRAY_NUM=$(echo ${DISKS} | nawk '{print NF}')
 export DISKSARRAY=$DISKS
 
-
 if is_linux; then
 	set_slice_prefix
 	set_device_dir
-#	export SLICE=1
-else
-	DEV_DSKDIR="/dev"
-	export SLICE_PREFIX="s"
-#	export SLICE=0
 fi
diff --git a/tests/zfs-tests/tests/functional/zvol/zvol_cli/zvol_cli.cfg b/tests/zfs-tests/tests/functional/zvol/zvol_cli/zvol_cli.cfg
index bede6694c0..8a99225ba9 100644
--- a/tests/zfs-tests/tests/functional/zvol/zvol_cli/zvol_cli.cfg
+++ b/tests/zfs-tests/tests/functional/zvol/zvol_cli/zvol_cli.cfg
@@ -35,11 +35,7 @@ verify_runnable "global"
 export DISK_ARRAY_NUM=$(echo ${DISKS} | nawk '{print NF}')
 export DISKSARRAY=$DISKS
 
-
 if is_linux; then
 	set_slice_prefix
 	set_device_dir
-else
-	DEV_DSKDIR="/dev"
-	export SLICE_PREFIX="s"
 fi