diff --git a/tests/test-runner/bin/test-runner.py.in b/tests/test-runner/bin/test-runner.py.in
index 5c868d945a..cb453b266f 100755
--- a/tests/test-runner/bin/test-runner.py.in
+++ b/tests/test-runner/bin/test-runner.py.in
@@ -291,7 +291,7 @@ User: %s
         self.result.starttime = monotonic_time()
 
         if kmemleak:
-            cmd = f'echo clear | {SUDO} tee {KMEMLEAK_FILE}'
+            cmd = f'{SUDO} sh -c "echo clear > {KMEMLEAK_FILE}"'
             check_output(cmd, shell=True)
 
         proc = Popen(privcmd, stdout=PIPE, stderr=PIPE)
@@ -305,7 +305,7 @@ User: %s
             self.result.stdout, self.result.stderr = self.collect_output(proc)
 
             if kmemleak:
-                cmd = f'echo scan | {SUDO} tee {KMEMLEAK_FILE}'
+                cmd = f'{SUDO} sh -c "echo scan > {KMEMLEAK_FILE}"'
                 check_output(cmd, shell=True)
                 cmd = f'{SUDO} cat {KMEMLEAK_FILE}'
                 self.result.kmemleak = check_output(cmd, shell=True)
@@ -880,7 +880,7 @@ class TestRun(object):
                       self.outputdir, LOG_ERR)
 
         if options.kmemleak:
-            cmd = f'echo scan=0 | {SUDO} tee {KMEMLEAK_FILE}'
+            cmd = f'{SUDO} -c "echo scan=0 > {KMEMLEAK_FILE}"'
             check_output(cmd, shell=True)
 
         iteration = 0
diff --git a/tests/zfs-tests/include/commands.cfg b/tests/zfs-tests/include/commands.cfg
index fcde48adc6..0951f719b9 100644
--- a/tests/zfs-tests/include/commands.cfg
+++ b/tests/zfs-tests/include/commands.cfg
@@ -8,9 +8,7 @@
 # Please keep the contents of each variable sorted for ease of reading
 # and maintenance.
 #
-export SYSTEM_FILES_COMMON='arp
-    awk
-    base64
+export SYSTEM_FILES_COMMON='awk
     basename
     bc
     bunzip2
@@ -52,10 +50,10 @@ export SYSTEM_FILES_COMMON='arp
     ksh
     ldd
     ln
-    logname
     ls
     mkdir
     mknod
+    mkfifo
     mktemp
     mount
     mv
@@ -67,12 +65,9 @@ export SYSTEM_FILES_COMMON='arp
     pgrep
     ping
     pkill
-    printenv
     printf
     ps
-    pwd
     python3
-    quotaon
     readlink
     rm
     rmdir
@@ -88,32 +83,26 @@ export SYSTEM_FILES_COMMON='arp
     ssh
     stat
     strings
-    su
     sudo
     swapoff
     swapon
     sync
     tail
     tar
-    tee
     timeout
     touch
     tr
     true
     truncate
-    umask
     umount
     uname
     uniq
-    uuidgen
     vmstat
-    wait
     wc'
 
 export SYSTEM_FILES_FREEBSD='chflags
     compress
     diskinfo
-    dumpon
     fsck
     getextattr
     gpart
@@ -123,7 +112,6 @@ export SYSTEM_FILES_FREEBSD='chflags
     lsextattr
     md5
     mdconfig
-    mkfifo
     newfs
     pw
     rmextattr
@@ -135,14 +123,11 @@ export SYSTEM_FILES_FREEBSD='chflags
     uncompress'
 
 export SYSTEM_FILES_LINUX='attr
-    bash
     blkid
     blockdev
     chattr
-    dmidecode
     exportfs
     fallocate
-    fdisk
     free
     getfattr
     groupadd
@@ -159,16 +144,17 @@ export SYSTEM_FILES_LINUX='attr
     mkswap
     modprobe
     mpstat
-    nproc
     parted
     perf
-    setenforce
     setfattr
     sha256sum
     udevadm
     useradd
     userdel
-    usermod'
+    usermod
+
+    flock
+    logger'
 
 export ZFS_FILES='zdb
     zfs
diff --git a/tests/zfs-tests/include/libtest.shlib b/tests/zfs-tests/include/libtest.shlib
index 88390456a1..5f0f2d56ac 100644
--- a/tests/zfs-tests/include/libtest.shlib
+++ b/tests/zfs-tests/include/libtest.shlib
@@ -2970,59 +2970,6 @@ function get_device_state #pool disk field("", "spares","logs")
 		($1==field || $1 ~ "^spares$" || $1 ~ "^logs$") {startfield=0}'
 }
 
-#
-# Given a disk, label it to VTOC regardless what label was on the disk
-# $1 disk
-#
-function labelvtoc
-{
-	typeset disk=$1
-	if [[ -z $disk ]]; then
-		log_fail "The disk name is unspecified."
-	fi
-	typeset label_file=/var/tmp/labelvtoc.$$
-	typeset arch=$(uname -p)
-
-	if is_linux || is_freebsd; then
-		log_note "Currently unsupported by the test framework"
-		return 1
-	fi
-
-	if [[ $arch == "i386" ]]; then
-		echo "label" > $label_file
-		echo "0" >> $label_file
-		echo "" >> $label_file
-		echo "q" >> $label_file
-		echo "q" >> $label_file
-
-		fdisk -B $disk >/dev/null 2>&1
-		# wait a while for fdisk finishes
-		sleep 60
-	elif [[ $arch == "sparc" ]]; then
-		echo "label" > $label_file
-		echo "0" >> $label_file
-		echo "" >> $label_file
-		echo "" >> $label_file
-		echo "" >> $label_file
-		echo "q" >> $label_file
-	else
-		log_fail "unknown arch type"
-	fi
-
-	format -e -s -d $disk -f $label_file
-	typeset -i ret_val=$?
-	rm -f $label_file
-	#
-	# wait the format to finish
-	#
-	sleep 60
-	if ((ret_val != 0)); then
-		log_fail "unable to label $disk as VTOC."
-	fi
-
-	return 0
-}
-
 #
 # get the root filesystem name if it's zfsroot system.
 #
@@ -3077,22 +3024,19 @@ function verify_disk_count
 function ds_is_volume
 {
 	typeset type=$(get_prop type $1)
-	[[ $type = "volume" ]] && return 0
-	return 1
+	[ $type = "volume" ]
 }
 
 function ds_is_filesystem
 {
 	typeset type=$(get_prop type $1)
-	[[ $type = "filesystem" ]] && return 0
-	return 1
+	[ $type = "filesystem" ]
 }
 
 function ds_is_snapshot
 {
 	typeset type=$(get_prop type $1)
-	[[ $type = "snapshot" ]] && return 0
-	return 1
+	[ $type = "snapshot" ]
 }
 
 #
@@ -3108,7 +3052,7 @@ function is_mp
 {
 	case $(uname) in
 		Linux)
-			(($(nproc) > 1))
+			(($(grep -c '^processor' /proc/cpuinfo) > 1))
 			;;
 		FreeBSD)
 			sysctl -n kern.smp.cpus
diff --git a/tests/zfs-tests/tests/functional/cli_root/zdb/zdb_block_size_histogram.ksh b/tests/zfs-tests/tests/functional/cli_root/zdb/zdb_block_size_histogram.ksh
index 75f15f6a88..9a960cecc3 100755
--- a/tests/zfs-tests/tests/functional/cli_root/zdb/zdb_block_size_histogram.ksh
+++ b/tests/zfs-tests/tests/functional/cli_root/zdb/zdb_block_size_histogram.ksh
@@ -145,7 +145,6 @@ function histo_check_test_pool
 	typeset -i this_rs
 	typeset -i this_ri
 	typeset -i sum_filesizes=0
-	typeset dumped
 	typeset stripped
 
 	let histo_check_pool_size=$(get_pool_prop size ${pool})
@@ -157,11 +156,9 @@ function histo_check_test_pool
 		log_fail "hctp: max_pool_record_size is not numeric ${max_pool_record_size}"
 	fi
 
-	dumped="${TEST_BASE_DIR}/${pool}_dump.txt"
 	stripped="${TEST_BASE_DIR}/${pool}_stripped.txt"
 
 	zdb -Pbbb ${pool} | \
-	    tee ${dumped} | \
 	    sed -e '1,/^block[ 	][ 	]*psize[ 	][ 	]*lsize.*$/d' \
 	    -e '/^size[ 	]*Count/d' -e '/^$/,$d' \
 	    > ${stripped}
diff --git a/tests/zfs-tests/tests/functional/cli_root/zfs_diff/zfs_diff_types.ksh b/tests/zfs-tests/tests/functional/cli_root/zfs_diff/zfs_diff_types.ksh
index 51f0295cd3..07b14e7aec 100755
--- a/tests/zfs-tests/tests/functional/cli_root/zfs_diff/zfs_diff_types.ksh
+++ b/tests/zfs-tests/tests/functional/cli_root/zfs_diff/zfs_diff_types.ksh
@@ -111,11 +111,7 @@ verify_object_class "$MNTPOINT/cdev" "C"
 
 # 2. | (Named pipe)
 log_must zfs snapshot "$TESTSNAP1"
-if is_freebsd; then
-    log_must mkfifo "$MNTPOINT/fifo"
-else
-    log_must mknod "$MNTPOINT/fifo" p
-fi
+log_must mkfifo "$MNTPOINT/fifo"
 log_must zfs snapshot "$TESTSNAP2"
 verify_object_class "$MNTPOINT/fifo" "|"
 
diff --git a/tests/zfs-tests/tests/functional/cli_root/zpool_create/zpool_create_024_pos.ksh b/tests/zfs-tests/tests/functional/cli_root/zpool_create/zpool_create_024_pos.ksh
index 5b464c3c24..98d2ee543b 100755
--- a/tests/zfs-tests/tests/functional/cli_root/zpool_create/zpool_create_024_pos.ksh
+++ b/tests/zfs-tests/tests/functional/cli_root/zpool_create/zpool_create_024_pos.ksh
@@ -74,7 +74,7 @@ child_pools=""
 
 function zpool_stress
 {
-	typeset pool=$1
+	typeset pool="$1-$$"
 	typeset vdev0="$TEST_BASE_DIR/$pool-vdev0.img"
 	typeset vdev1="$TEST_BASE_DIR/$pool-vdev1.img"
 	typeset -i iters=$2
@@ -118,13 +118,11 @@ function zpool_stress
 # 1. Create 128 process each of which create/destroy a pool 5 times.
 typeset i=0
 while [[ $i -lt 128 ]]; do
-	typeset uuid=$(uuidgen | cut -c1-13)
-
-	zpool_stress $TESTPOOL-$uuid 5 &
+	zpool_stress $TESTPOOL-$i 5 &
 	typeset pid=$!
 
 	child_pids="$child_pids $pid"
-	child_pools="$child_pools $TESTPOOL-$uuid"
+	child_pools="$child_pools $TESTPOOL-$i-$pid"
 	((i = i + 1))
 done
 
diff --git a/tests/zfs-tests/tests/functional/cli_user/misc/zfs_allow_001_neg.ksh b/tests/zfs-tests/tests/functional/cli_user/misc/zfs_allow_001_neg.ksh
index 56a74e4ae4..ce474657b4 100755
--- a/tests/zfs-tests/tests/functional/cli_user/misc/zfs_allow_001_neg.ksh
+++ b/tests/zfs-tests/tests/functional/cli_user/misc/zfs_allow_001_neg.ksh
@@ -44,22 +44,15 @@
 #
 #
 
-# check to see if we have zfs allow
-zfs 2>&1 | grep "allow" > /dev/null
-if (($? != 0)) then
-	log_unsupported "ZFS allow not supported on this machine."
-fi
-
 log_assert "zfs allow returns an error when run as a user"
 
 log_must zfs allow $TESTPOOL/$TESTFS
-log_mustnot zfs allow $(logname) create $TESTPOOL/$TESTFS
+log_mustnot zfs allow $(id -un) create $TESTPOOL/$TESTFS
 
 # now verify that the above command actually did nothing by
 # checking for any allow output. ( if no allows are granted,
 # nothing should be output )
-OUTPUT=$(zfs allow $TESTPOOL/$TESTFS | grep "Local+Descendent" )
-if [ -n "$OUTPUT" ]
+if zfs allow $TESTPOOL/$TESTFS | grep -q "Local+Descendent"
 then
 	log_fail "zfs allow permissions were granted on $TESTPOOL/$TESTFS"
 fi
diff --git a/tests/zfs-tests/tests/functional/cp_files/cp_files_001_pos.ksh b/tests/zfs-tests/tests/functional/cp_files/cp_files_001_pos.ksh
index 3e138cfc9f..208ecfeed3 100755
--- a/tests/zfs-tests/tests/functional/cp_files/cp_files_001_pos.ksh
+++ b/tests/zfs-tests/tests/functional/cp_files/cp_files_001_pos.ksh
@@ -58,7 +58,7 @@ BATCH=1000
 log_must mkdir $TESTDIR/src
 log_must mkdir $TESTDIR/dst
 
-WD=$(pwd)
+WD=$PWD
 cd $TESTDIR/src
 # create NR_FILES in BATCH at a time to prevent overflowing argument buffer
 for i in $(seq $(($NR_FILES/$BATCH))); do touch $(seq $((($i-1)*$BATCH+1)) $(($i*$BATCH))); done
diff --git a/tests/zfs-tests/tests/functional/mmp/mmp.kshlib b/tests/zfs-tests/tests/functional/mmp/mmp.kshlib
index 7ff2636e1f..636d2fa686 100644
--- a/tests/zfs-tests/tests/functional/mmp/mmp.kshlib
+++ b/tests/zfs-tests/tests/functional/mmp/mmp.kshlib
@@ -69,8 +69,6 @@ function try_pool_import # pool opts message
 	typeset msg=$3
 
 	zpool import $opts $pool 2>&1 | grep -i "$msg"
-
-	return $?
 }
 
 function mmp_set_hostid
@@ -79,11 +77,7 @@ function mmp_set_hostid
 
 	zgenhostid $1
 
-	if [ $(hostid) != "$hostid" ]; then
-		return 1
-	fi
-
-	return 0
+	[ $(hostid) = "$hostid" ]
 }
 
 function mmp_clear_hostid
diff --git a/tests/zfs-tests/tests/functional/xattr/xattr_003_neg.ksh b/tests/zfs-tests/tests/functional/xattr/xattr_003_neg.ksh
index ba27d043b7..852bffc7a1 100755
--- a/tests/zfs-tests/tests/functional/xattr/xattr_003_neg.ksh
+++ b/tests/zfs-tests/tests/functional/xattr/xattr_003_neg.ksh
@@ -59,8 +59,8 @@ create_xattr $testfile passwd /etc/passwd
 
 log_must chmod 000 $testfile
 if is_illumos; then
-	log_mustnot su $ZFS_USER -c "runat $testfile cat passwd"
-	log_mustnot su $ZFS_USER -c "runat $testfile cp /etc/passwd ."
+	log_mustnot user_run $ZFS_USER runat $testfile cat passwd
+	log_mustnot user_run $ZFS_USER runat $testfile cp /etc/passwd .
 else
 	log_mustnot user_run $ZFS_USER "
 . $STF_SUITE/include/libtest.shlib
diff --git a/tests/zfs-tests/tests/functional/xattr/xattr_010_neg.ksh b/tests/zfs-tests/tests/functional/xattr/xattr_010_neg.ksh
index 43502bfff2..41c7054f23 100755
--- a/tests/zfs-tests/tests/functional/xattr/xattr_010_neg.ksh
+++ b/tests/zfs-tests/tests/functional/xattr/xattr_010_neg.ksh
@@ -61,6 +61,6 @@ log_mustnot runat $TESTDIR/myfile.$$ mknod block b 888 888
 
 log_mustnot runat $TESTDIR/myfile.$$ mknod char c
 
-log_mustnot runat $TESTDIR/myfile.$$ mknod fifo p
+log_mustnot runat $TESTDIR/myfile.$$ mkfifo fifo
 
 log_pass "mkdir, mknod fail"
diff --git a/tests/zfs-tests/tests/perf/perf.shlib b/tests/zfs-tests/tests/perf/perf.shlib
index 27f56676db..c9b4505e23 100644
--- a/tests/zfs-tests/tests/perf/perf.shlib
+++ b/tests/zfs-tests/tests/perf/perf.shlib
@@ -254,7 +254,7 @@ function do_collect_scripts
 # Find a place to deposit performance data collected while under load.
 function get_perf_output_dir
 {
-	typeset dir="$(pwd)/perf_data"
+	typeset dir="$PWD/perf_data"
 	[[ -d $dir ]] || mkdir -p $dir
 
 	echo $dir
@@ -467,7 +467,7 @@ function get_system_config
 
 	echo "{" >>$config
 	if is_linux; then
-		echo "  \"ncpus\": \"$(nproc --all)\"," >>$config
+		echo "  \"ncpus\": \"$(lscpu | awk '/^CPU\(s\)/ {print $2; exit}')\"," >>$config
 		echo "  \"physmem\": \"$(free -b | \
 		    awk '$1 == "Mem:" { print $2 }')\"," >>$config
 		echo "  \"c_max\": \"$(get_max_arc_size)\"," >>$config
diff --git a/tests/zfs-tests/tests/perf/scripts/prefetch_io.sh b/tests/zfs-tests/tests/perf/scripts/prefetch_io.sh
index 07688ef21b..bc2bb11aef 100755
--- a/tests/zfs-tests/tests/perf/scripts/prefetch_io.sh
+++ b/tests/zfs-tests/tests/perf/scripts/prefetch_io.sh
@@ -1,5 +1,4 @@
-#!/usr/bin/env bash
-# shellcheck disable=SC1004
+#!/bin/sh
 
 #
 # This file and its contents are supplied under the terms of the
@@ -21,33 +20,12 @@
 # TBD if we can add additional kstats to achieve the desired results
 #
 
-zfs_kstats="/proc/spl/kstat/zfs"
-
-function get_prefetch_ios
-{
-	typeset -l data_misses="$(awk '$1 == "prefetch_data_misses" \
-	    { print $3; exit }' "$zfs_kstats/arcstats")"
-	typeset -l metadata_misses="$(awk '$1 == "prefetch_metadata_misses" \
-	    { print $3; exit }' "$zfs_kstats/arcstats")"
-	typeset -l total_misses=$(( data_misses + metadata_misses ))
-
-	echo "$total_misses"
+getstat() {
+	awk -v c="$1" '$1 == c {print $3; exit}' /proc/spl/kstat/zfs/arcstats
 }
 
-function get_prefetched_demand_reads
-{
-	typeset -l demand_reads="$(awk '$1 == "demand_hit_predictive_prefetch" \
-	    { print $3; exit }' "$zfs_kstats/arcstats")"
-
-	echo "$demand_reads"
-}
-
-function get_async_upgrade_sync
-{
-	typeset -l sync_wait="$(awk '$1 == "async_upgrade_sync" \
-	    { print $3; exit }' "$zfs_kstats/arcstats")"
-
-	echo "$sync_wait"
+get_prefetch_ios() {
+	echo $(( $(getstat prefetch_data_misses) + $(getstat prefetch_metadata_misses) ))
 }
 
 if [ $# -ne 2 ]
@@ -58,8 +36,8 @@ fi
 
 interval=$2
 prefetch_ios=$(get_prefetch_ios)
-prefetched_demand_reads=$(get_prefetched_demand_reads)
-async_upgrade_sync=$(get_async_upgrade_sync)
+prefetched_demand_reads=$(getstat demand_hit_predictive_prefetch)
+async_upgrade_sync=$(getstat async_upgrade_sync)
 
 while true
 do
@@ -68,12 +46,12 @@ do
 	    $(( new_prefetch_ios - prefetch_ios ))
 	prefetch_ios=$new_prefetch_ios
 
-	new_prefetched_demand_reads=$(get_prefetched_demand_reads)
+	new_prefetched_demand_reads=$(getstat demand_hit_predictive_prefetch)
 	printf '%-24s\t%u\n' "prefetched_demand_reads" \
 	    $(( new_prefetched_demand_reads - prefetched_demand_reads ))
 	prefetched_demand_reads=$new_prefetched_demand_reads
 
-	new_async_upgrade_sync=$(get_async_upgrade_sync)
+	new_async_upgrade_sync=$(getstat async_upgrade_sync)
 	printf '%-24s\t%u\n' "async_upgrade_sync" \
 	    $(( new_async_upgrade_sync - async_upgrade_sync ))
 	async_upgrade_sync=$new_async_upgrade_sync