Make test more resilient

Signed-off-by: Paul Dagnelie <[email protected]>

Author: Paul Dagnelie

tests/zfs-tests/tests/functional/cli_root/zpool_initialize/zpool_initialize_online_offline.ksh

@@ -52,6 +52,10 @@ for type in "mirror" "anyraid1"; do
 		log_must zpool create -f $TESTPOOL $type $DISK1 $DISK2
 	else
 		log_must zpool create -f $TESTPOOL $type $DISK1 $DISK2 $DISK3
+		log_must dd if=/dev/urandom of=/$TESTPOOL/f1 bs=1M count=100
+		log_must zpool sync
+		log_must rm /$TESTPOOL/f1
+		log_must zpool sync
 	fi
 	log_must zpool initialize $TESTPOOL $DISK1