diff --git a/tests/zfs-tests/tests/functional/cli_root/zfs_copies/zfs_copies.kshlib b/tests/zfs-tests/tests/functional/cli_root/zfs_copies/zfs_copies.kshlib
index 5617bd01ba42..9911ccdf536d 100644
--- a/tests/zfs-tests/tests/functional/cli_root/zfs_copies/zfs_copies.kshlib
+++ b/tests/zfs-tests/tests/functional/cli_root/zfs_copies/zfs_copies.kshlib
@@ -1,157 +1,157 @@
 #
 # CDDL HEADER START
 #
 # The contents of this file are subject to the terms of the
 # Common Development and Distribution License (the "License").
 # You may not use this file except in compliance with the License.
 #
 # You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 # or https://opensource.org/licenses/CDDL-1.0.
 # See the License for the specific language governing permissions
 # and limitations under the License.
 #
 # When distributing Covered Code, include this CDDL HEADER in each
 # file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 # If applicable, add the following below this CDDL HEADER, with the
 # fields enclosed by brackets "[]" replaced with your own identifying
 # information: Portions Copyright [yyyy] [name of copyright owner]
 #
 # CDDL HEADER END
 #
 
 #
 # Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
 # Use is subject to license terms.
 #
 
 #
 # Copyright (c) 2012, 2016 by Delphix. All rights reserved.
 #
 
 . $STF_SUITE/include/libtest.shlib
 . $STF_SUITE/tests/functional/cli_root/zfs_copies/zfs_copies.cfg
 
 #
 # Compare the value of copies property with specified value
 # $1, the dataset name
 # $2, the expected copies value
 #
 function cmp_prop
 {
 	typeset ds=$1
 	typeset	val_expect=$2
 	typeset val_actual
 
 	val_actual=$(get_prop copies $ds)
 	if [[ $val_actual != $val_expect ]]; then
 		log_fail "Expected value ($val_expect) != actual value " \
 		    "($val_actual)"
 	fi
 }
 
 #
 # Check the used space is charged correctly
 # $1, the number of used space
 # $2, the expected common factor between the used space and the file space
 #
 function check_used
 {
 	typeset charged_spc=$1
 	typeset -i used
 	typeset -i expected_cfactor=$2
 	typeset -i cfactor
 	typeset -i fsize=${FILESIZE%[m|M]}
 
 	((used = $charged_spc / 1024 / 1024))
 	((cfactor = used / fsize))
 	if ((cfactor != expected_cfactor)); then
 		log_fail "The space is not charged correctly while setting" \
 		    "copies as $expected_cfactor."
 	fi
 }
 
 #
 # test ncopies on volume
 # $1  test type zfs|ufs|ext2
 # $2  copies
 # $3  mntp for ufs|ext2 test
 function do_vol_test
 {
 	typeset type=$1
 	typeset copies=$2
 	typeset mntp=$3
 
 	vol=$TESTPOOL/$TESTVOL1
 	vol_b_path=$ZVOL_DEVDIR/$TESTPOOL/$TESTVOL1
 
-	log_must zfs create -V $VOLSIZE -o copies=$copies $vol
+	log_must zfs create -V $VOLSIZE -o compression=off -o copies=$copies \
+	    $vol
 	log_must zfs set refreservation=none $vol
 	block_device_wait $vol_b_path
 
 	case "$type" in
 	"ext2")
 		if is_freebsd; then
 			log_unsupported "ext2 test not implemented for freebsd"
 		fi
 		log_must eval "new_fs $vol_b_path >/dev/null 2>&1"
 		log_must mount -o rw $vol_b_path $mntp
 		;;
 	"ufs")
 		if is_linux; then
 			log_unsupported "ufs test not implemented for linux"
 		fi
 		log_must eval "new_fs $vol_b_path >/dev/null 2>&1"
 		log_must mount $vol_b_path $mntp
 		;;
 	"zfs")
 		if is_freebsd; then
 			# Pool creation on zvols is forbidden by default.
 			# Save and restore the current setting.
 			typeset _saved=$(get_tunable VOL_RECURSIVE)
 			log_must set_tunable64 VOL_RECURSIVE 1 # Allow
 			zpool create $TESTPOOL1 $vol_b_path
 			typeset _zpool_create_result=$?
 			log_must set_tunable64 VOL_RECURSIVE $_saved # Restore
 			log_must test $_zpool_create_result = 0
 		else
 			log_must zpool create $TESTPOOL1 $vol_b_path
 		fi
-		log_must zfs create $TESTPOOL1/$TESTFS1
+		log_must zfs create -o compression=off $TESTPOOL1/$TESTFS1
+		sync_pool $TESTPOOL1
 		;;
 	*)
 		log_unsupported "$type test not implemented"
 		;;
 	esac
 
-	((nfilesize = copies * ${FILESIZE%m}))
+	sync_pool $TESTPOOL
 	pre_used=$(get_prop used $vol)
-	((target_size = pre_used + nfilesize))
 
 	if [[ $type == "zfs" ]]; then
 		log_must mkfile $FILESIZE /$TESTPOOL1/$TESTFS1/$FILE
+		sync_pool $TESTPOOL1
 	else
 		log_must mkfile $FILESIZE $mntp/$FILE
+		log_must sync
 	fi
 
+	sync_pool $TESTPOOL
 	post_used=$(get_prop used $vol)
-	((retries = 0))
-	while ((post_used < target_size && retries++ < 42)); do
-		sleep 1
-		post_used=$(get_prop used $vol)
-	done
 
 	((used = post_used - pre_used))
+	((nfilesize = copies * ${FILESIZE%m}))
 	if ((used < nfilesize)); then
 		log_fail "The space is not charged correctly while setting" \
 		    "copies as $copies ($used < $nfilesize)" \
 		    "pre=${pre_used} post=${post_used}"
 	fi
 
 	if [[ $type == "zfs" ]]; then
 		log_must zpool destroy $TESTPOOL1
 	else
 		log_must umount $mntp
 	fi
 
 	log_must zfs destroy $vol
 }