diff --git a/bin/alluxio-mount.sh b/bin/alluxio-mount.sh
index 0710738d1a9e..576309d8aa8b 100755
--- a/bin/alluxio-mount.sh
+++ b/bin/alluxio-mount.sh
@@ -29,9 +29,61 @@ function init_env() {
   local libexec_dir=${ALLUXIO_LIBEXEC_DIR:-"${BIN}"/../libexec}
   . ${libexec_dir}/alluxio-config.sh
 
-  MEM_SIZE=$(${BIN}/alluxio getConf alluxio.worker.memory.size)
-  TIER_ALIAS=$(${BIN}/alluxio getConf alluxio.worker.tieredstore.level0.alias)
-  TIER_PATH=$(${BIN}/alluxio getConf alluxio.worker.tieredstore.level0.dirs.path)
+  # Determine a reasonable default for worker memory
+  if [[ $(uname -s) == Darwin ]]; then
+    # Assuming Mac OS X
+    local default_total_mem=$(sysctl hw.memsize | cut -d ' ' -f2)
+    default_total_mem=$[default_total_mem / 1024 / 1024]
+    default_total_mem=$[default_total_mem * 2 / 3]MB
+  else
+    # Assuming Linux
+    local default_total_mem=$(awk '/MemTotal/{print $2}' /proc/meminfo)
+    default_total_mem=$[TOTAL_MEM / 1024 * 2 / 3]MB
+  fi
+  local worker_mem_size=$(${BIN}/alluxio getConf alluxio.worker.memory.size)
+  worker_mem_size=${worker_mem_size:-${default_total_mem}}
+
+  MEM_SIZE=$(echo "${worker_mem_size}" | tr -s '[:upper:]' '[:lower:]')
+}
+
+#enable the regexp case match
+shopt -s extglob
+function mem_size_to_bytes() {
+  float_scale=2
+  function float_eval() {
+    local stat=0
+    local result=0.0
+    if [[ $# -gt 0 ]]; then
+      result=$(echo "scale=${float_scale}; $*" | bc -q 2>/dev/null)
+      stat=$?
+      if [[ ${stat} -eq 0  &&  -z "${result}" ]]; then stat=1; fi
+    fi
+    echo $( printf "%.0f" ${result} )
+    return $( printf "%.0f" ${stat} )
+  }
+
+  SIZE=${MEM_SIZE//[^0-9.]/}
+  case ${MEM_SIZE} in
+    *g?(b) )
+      # Size was specified in gigabytes.
+      BYTE_SIZE=$(float_eval "${SIZE} * 1024 * 1024 * 1024")
+      ;;
+    *m?(b))
+      # Size was specified in megabytes.
+      BYTE_SIZE=$(float_eval "${SIZE} * 1024 * 1024")
+      ;;
+    *k?(b))
+      # Size was specified in kilobytes.
+      BYTE_SIZE=$(float_eval "${SIZE} * 1024")
+      ;;
+    +([0-9])?(b))
+      # Size was specified in bytes.
+      BYTE_SIZE=${SIZE}
+      ;;
+    *)
+      echo "Please specify ALLUXIO_WORKER_MEMORY_SIZE in a correct form." >&2
+      exit 1
+  esac
 }
 
 # Mac OS X HFS+ provisioning
@@ -93,82 +145,97 @@ function mac_hfs_provision_sectors() {
 }
 
 function mount_ramfs_linux() {
-  local total_mem=$(($(cat /proc/meminfo | awk 'NR==1{print $2}') * 1024))
-  if [[ ${total_mem} -lt ${MEM_SIZE} ]]; then
-    echo "ERROR: Memory(${total_mem}) is less than requested ramdisk size(${MEM_SIZE}). Please
-    reduce alluxio.worker.memory.size in alluxio-site.properties" >&2
+  init_env $1
+
+  if [[ -z ${ALLUXIO_RAM_FOLDER} ]]; then
+    ALLUXIO_RAM_FOLDER=/mnt/ramdisk
+    echo "ALLUXIO_RAM_FOLDER was not set. Using the default one: ${ALLUXIO_RAM_FOLDER}"
+  fi
+
+  mem_size_to_bytes
+  TOTAL_MEM=$(($(cat /proc/meminfo | awk 'NR==1{print $2}') * 1024))
+  if [[ ${TOTAL_MEM} -lt ${BYTE_SIZE} ]]; then
+    echo "ERROR: Memory(${TOTAL_MEM}) is less than requested ramdisk size(${BYTE_SIZE}). Please
+    reduce ALLUXIO_WORKER_MEMORY_SIZE" >&2
     exit 1
   fi
 
-  echo "Formatting RamFS: ${TIER_PATH} (${MEM_SIZE})"
-  if mount | grep ${TIER_PATH} > /dev/null; then
-    umount -f ${TIER_PATH}
+  F=${ALLUXIO_RAM_FOLDER}
+  echo "Formatting RamFS: ${F} (${MEM_SIZE})"
+  if mount | grep ${F} > /dev/null; then
+    umount -f ${F}
     if [[ $? -ne 0 ]]; then
-      echo "ERROR: umount RamFS ${TIER_PATH} failed" >&2
+      echo "ERROR: umount RamFS ${F} failed" >&2
       exit 1
     fi
   else
-    mkdir -p ${TIER_PATH}
+    mkdir -p ${F}
   fi
 
-  mount -t ramfs -o size=${MEM_SIZE} ramfs ${TIER_PATH} ; chmod a+w ${TIER_PATH} ;
+  mount -t ramfs -o size=${MEM_SIZE} ramfs ${F} ; chmod a+w ${F} ;
 }
 
 function mount_ramfs_mac() {
-  # Convert the memory size to number of sectors. Each sector is 512 Byte.
-  local num_sectors=$(mac_hfs_provision_sectors ${MEM_SIZE} 512)
+  init_env $0
 
-  # Format the RAM FS
-  # We may have a pre-existing RAM FS which we need to throw away
-  echo "Formatting RamFS: ${TIER_PATH} ${num_sectors} sectors (${MEM_SIZE})."
-  local device=$(df -l | grep ${TIER_PATH} | cut -d " " -f 1)
-  if [[ -n "${device}" ]]; then
-    hdiutil detach -force ${device}
+  if [[ -z ${ALLUXIO_RAM_FOLDER} ]]; then
+    ALLUXIO_RAM_FOLDER=/Volumes/ramdisk
+    echo "ALLUXIO_RAM_FOLDER was not set. Using the default one: ${ALLUXIO_RAM_FOLDER}"
+  fi
+
+  if [[ ${ALLUXIO_RAM_FOLDER} != "/Volumes/"* ]]; then
+    echo "Invalid ALLUXIO_RAM_FOLDER: ${ALLUXIO_RAM_FOLDER}" >&2
+    echo "ALLUXIO_RAM_FOLDER must set to /Volumes/[name] on Mac OS X." >&2
+    exit 1
   fi
+
   # Remove the "/Volumes/" part so we can get the name of the volume.
-  diskutil erasevolume HFS+ ${TIER_PATH/#\/Volumes\//} $(hdiutil attach -nomount ram://${num_sectors})
-}
+  F=${ALLUXIO_RAM_FOLDER/#\/Volumes\//}
 
-function mount_ramfs_local() {
-  init_env
+  # Convert the memory size to number of sectors. Each sector is 512 Byte.
+  mem_size_to_bytes
+  NUM_SECTORS=$(mac_hfs_provision_sectors ${BYTE_SIZE} 512)
 
-  if [[ ${TIER_ALIAS} != "MEM" ]]; then
-    # the top tier is not MEM, skip
-    exit 1
+  # Format the RAM FS
+  # We may have a pre-existing RAM FS which we need to throw away
+  echo "Formatting RamFS: ${F} ${NUM_SECTORS} sectors (${MEM_SIZE})."
+  DEVICE=$(df -l | grep ${F} | cut -d " " -f 1)
+  if [[ -n "${DEVICE}" ]]; then
+    hdiutil detach -force ${DEVICE}
   fi
+  diskutil erasevolume HFS+ ${F} $(hdiutil attach -nomount ram://${NUM_SECTORS})
+}
 
+function mount_local() {
   if [[ $(uname -a) == Darwin* ]]; then
     # Assuming Mac OS X
     mount_ramfs_mac
   else
     # Assuming Linux
     if [[ "$1" == "SudoMount" ]]; then
-      sudo bash -O extglob -c "mount_ramfs_linux"
+      DECL_INIT=$(declare -f init_env)
+      DECL_MEM_SIZE_TO_BYTES=$(declare -f mem_size_to_bytes)
+      DECL_MOUNT_LINUX=$(declare -f mount_ramfs_linux)
+      sudo bash -O extglob -c "ALLUXIO_CONF_DIR=${ALLUXIO_CONF_DIR}; BIN=${BIN}; ${DECL_INIT}; \
+${DECL_MEM_SIZE_TO_BYTES}; ${DECL_MOUNT_LINUX}; mount_ramfs_linux $0"
     else
-      mount_ramfs_linux
+      mount_ramfs_linux $0
     fi
   fi
 }
 
-function main {
-  case "${1}" in
-    Mount|SudoMount)
-      case "${2}" in
-        ""|local)
-          mount_ramfs_local $1
-          ;;
-        workers)
-          ${LAUNCHER} ${BIN}/alluxio-workers.sh ${BIN}/alluxio-mount.sh $1
-          ;;
-        *)
-          echo -e ${USAGE} >&2
-          exit 1
-      esac
-      ;;
-    *)
-      echo -e ${USAGE} >&2
-      exit 1
-  esac
-}
-
-main "$@"
+case "${1}" in
+  Mount|SudoMount)
+    case "${2}" in
+      ""|local)
+        mount_local $1
+        ;;
+      workers)
+        ${LAUNCHER} ${BIN}/alluxio-workers.sh ${BIN}/alluxio-mount.sh $1
+        ;;
+    esac
+    ;;
+  *)
+    echo -e ${USAGE} >&2
+    exit 1
+esac
diff --git a/bin/alluxio-start.sh b/bin/alluxio-start.sh
index c32d3790a81d..9a4d2812253f 100755
--- a/bin/alluxio-start.sh
+++ b/bin/alluxio-start.sh
@@ -37,8 +37,7 @@ MOPT (Mount Option) is one of:
   SudoMount\tMount the configured RamFS using sudo.
            \tNotice: this will format the existing RamFS.
   NoMount  \tDo not mount the configured RamFS.
-           \tNotice: to avoid sudo requirement but using tmpFS in Linux,
-             set ALLUXIO_RAM_FOLDER=/dev/shm on each worker and use NoMount.
+           \tNotice: Use NoMount (Linux only) to use tmpFS to avoid sudo requirement.
   SudoMount is assumed if MOPT is not specified.
 
 -f  format Journal, UnderFS Data and Workers Folder on master
@@ -59,9 +58,11 @@ get_env() {
   . ${ALLUXIO_LIBEXEC_DIR}/alluxio-config.sh
 }
 
-# Pass ram folder to check as $1
-# Return 0 if ram folder is mounted as tmpfs or ramfs, 1 otherwise
+# The exit status is 0 if ALLUXIO_RAM_FOLDER is mounted as tmpfs or ramfs.
 is_ram_folder_mounted() {
+  if [[ -z ${ALLUXIO_RAM_FOLDER} ]]; then
+    return 1
+  fi
   local mounted_fs=""
   if [[ $(uname -s) == Darwin ]]; then
     mounted_fs=$(mount -t "hfs" | grep '/Volumes/' | cut -d " " -f 3)
@@ -70,7 +71,8 @@ is_ram_folder_mounted() {
   fi
 
   for fs in ${mounted_fs}; do
-    if [[ "${1}" == "${fs}" || "${1}" =~ ^"${fs}"\/.* ]]; then
+    if [[ "${ALLUXIO_RAM_FOLDER}" == "${fs}" || \
+     "${ALLUXIO_RAM_FOLDER}" =~ ^"${fs}"\/.* ]]; then
       return 0
     fi
   done
@@ -83,26 +85,25 @@ check_mount_mode() {
     Mount);;
     SudoMount);;
     NoMount)
-      local tier_alias=$(${BIN}/alluxio getConf alluxio.worker.tieredstore.level0.alias)
-      local tier_path=$(${BIN}/alluxio getConf alluxio.worker.tieredstore.level0.dirs.path)
-      if [[ ${tier_alias} != "MEM" ]]; then
-        # if the top tier is not MEM, skip check
-        return
-      fi
-      is_ram_folder_mounted "${tier_path}"
+      is_ram_folder_mounted
       if [[ $? -ne 0 ]]; then
         if [[ $(uname -s) == Darwin ]]; then
           # Assuming Mac OS X
           echo "ERROR: NoMount is not supported on Mac OS X." >&2
           echo -e "${USAGE}" >&2
           exit 1
+        else
+          echo "WARNING: Overriding ALLUXIO_RAM_FOLDER to /dev/shm to use tmpFS now."
+          export ALLUXIO_RAM_FOLDER="/dev/shm"
+          # Set env again since some env variables depend on ALLUXIO_RAM_FOLDER.
+          get_env
         fi
       fi
-      if [[ "${tier_path}" =~ ^"/dev/shm"\/{0,1}$ ]]; then
-        echo "WARNING: Using tmpFS does not guarantee data to be stored in memory."
+      if [[ "${ALLUXIO_RAM_FOLDER}" =~ ^"/dev/shm"\/{0,1}$ ]]; then
+        echo "WARNING: Using tmpFS which is not guaranteed to be in memory."
         echo "WARNING: Check vmstat for memory statistics (e.g. swapping)."
       fi
-      ;;
+    ;;
     *)
       if [[ -z $1 ]]; then
         echo "This command requires a mount mode be specified" >&2
@@ -119,7 +120,7 @@ do_mount() {
   MOUNT_FAILED=0
   case "$1" in
     Mount|SudoMount)
-      ${LAUNCHER} "${BIN}/alluxio-mount.sh" $1
+      ${LAUNCHER} ${BIN}/alluxio-mount.sh $1
       MOUNT_FAILED=$?
       ;;
     NoMount)
diff --git a/core/common/src/main/java/alluxio/Configuration.java b/core/common/src/main/java/alluxio/Configuration.java
index b084f21d64ec..860e8ab1bb8d 100644
--- a/core/common/src/main/java/alluxio/Configuration.java
+++ b/core/common/src/main/java/alluxio/Configuration.java
@@ -16,18 +16,15 @@
 import alluxio.network.ChannelType;
 import alluxio.util.ConfigurationUtils;
 import alluxio.util.FormatUtils;
-import alluxio.util.OSUtils;
 
 import com.google.common.base.Preconditions;
 import com.google.common.base.Splitter;
 import com.google.common.base.Throwables;
 import com.google.common.collect.Lists;
-import com.sun.management.OperatingSystemMXBean;
 import io.netty.util.internal.chmv8.ConcurrentHashMapV8;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-import java.lang.management.ManagementFactory;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.List;
@@ -68,7 +65,8 @@ public final class Configuration {
   /** Regex to find ${key} for variable substitution. */
   private static final Pattern CONF_REGEX = Pattern.compile(REGEX_STRING);
   /** Map of properties. */
-  private static final ConcurrentHashMapV8<String, String> PROPERTIES = new ConcurrentHashMapV8<>();
+  private static final ConcurrentHashMapV8<String, String> PROPERTIES =
+      new ConcurrentHashMapV8<>();
 
   /** File to set customized properties for Alluxio server (both master and worker) and client. */
   public static final String SITE_PROPERTIES = "alluxio-site.properties";
@@ -85,7 +83,18 @@ public final class Configuration {
    */
   public static void defaultInit() {
     // Load default
-    Properties defaultProps = createDefaultProps();
+    Properties defaultProps = new Properties();
+    for (PropertyKey key : PropertyKey.values()) {
+      String value = key.getDefaultValue();
+      if (value != null) {
+        defaultProps.setProperty(key.toString(), value);
+      }
+    }
+    // Override runtime default
+    defaultProps.setProperty(PropertyKey.WORKER_NETWORK_NETTY_CHANNEL.toString(),
+        String.valueOf(ChannelType.defaultType()));
+    defaultProps.setProperty(PropertyKey.USER_NETWORK_NETTY_CHANNEL.toString(),
+        String.valueOf(ChannelType.defaultType()));
 
     // Load system properties
     Properties systemProps = new Properties();
@@ -124,46 +133,6 @@ public static void defaultInit() {
     checkConfigurationValues();
   }
 
-  /**
-   * @return default properties
-   */
-  private static Properties createDefaultProps() {
-    Properties defaultProps = new Properties();
-    // Load compile-time default
-    for (PropertyKey key : PropertyKey.values()) {
-      String value = key.getDefaultValue();
-      if (value != null) {
-        defaultProps.setProperty(key.toString(), value);
-      }
-    }
-
-    // Load run-time default
-    defaultProps.setProperty(PropertyKey.WORKER_NETWORK_NETTY_CHANNEL.toString(),
-        String.valueOf(ChannelType.defaultType()));
-    defaultProps.setProperty(PropertyKey.USER_NETWORK_NETTY_CHANNEL.toString(),
-        String.valueOf(ChannelType.defaultType()));
-    // Set ramdisk volume according to OS type
-    if (OSUtils.isLinux()) {
-      defaultProps
-          .setProperty(PropertyKey.WORKER_TIERED_STORE_LEVEL0_DIRS_PATH.toString(), "/mnt/ramdisk");
-    } else if (OSUtils.isMacOS()) {
-      defaultProps.setProperty(PropertyKey.WORKER_TIERED_STORE_LEVEL0_DIRS_PATH.toString(),
-          "/Volumes/ramdisk");
-    }
-    // Set a reasonable default size for worker memory
-    try {
-      OperatingSystemMXBean operatingSystemMXBean =
-          (OperatingSystemMXBean) ManagementFactory.getOperatingSystemMXBean();
-      long memSize = operatingSystemMXBean.getTotalPhysicalMemorySize();
-      defaultProps
-          .setProperty(PropertyKey.WORKER_MEMORY_SIZE.toString(), String.valueOf(memSize * 2 / 3));
-    } catch (Exception e) {
-      // The package com.sun.management may not be available on every platform.
-      // fallback to the compile-time default value
-    }
-    return defaultProps;
-  }
-
   /**
    * Merges the current configuration properties with alternate properties. A property from the new
    * configuration wins if it also appears in the current configuration.
diff --git a/core/common/src/main/java/alluxio/util/OSUtils.java b/core/common/src/main/java/alluxio/util/OSUtils.java
index 4b86dac1d73f..bf892d6a2718 100644
--- a/core/common/src/main/java/alluxio/util/OSUtils.java
+++ b/core/common/src/main/java/alluxio/util/OSUtils.java
@@ -43,20 +43,6 @@ public static boolean isWindows() {
     return SystemUtils.IS_OS_WINDOWS;
   }
 
-  /**
-   * @return true if current OS is MacOS
-   */
-  public static boolean isMacOS() {
-    return SystemUtils.IS_OS_MAC_OSX;
-  }
-
-  /**
-   * @return true if current OS is Linux
-   */
-  public static boolean isLinux() {
-    return SystemUtils.IS_OS_LINUX;
-  }
-
   /**
    * @return true if current OS is AIX
    */
diff --git a/libexec/alluxio-config.sh b/libexec/alluxio-config.sh
index 10df48c2bc1a..f3aa7336edc9 100755
--- a/libexec/alluxio-config.sh
+++ b/libexec/alluxio-config.sh
@@ -50,6 +50,19 @@ if [[ -e "${ALLUXIO_CONF_DIR}/alluxio-env.sh" ]]; then
   . "${ALLUXIO_CONF_DIR}/alluxio-env.sh"
 fi
 
+# Determine reasonable defaults for worker memory and ramdisk folder
+if [[ $(uname -s) == Darwin ]]; then
+  # Assuming Mac OS X
+  DEFAULT_RAM_FOLDER="/Volumes/ramdisk"
+else
+  # Assuming Linux
+  DEFAULT_RAM_FOLDER="/mnt/ramdisk"
+fi
+# If ALLUXIO_RAM_FOLDER is explicitly set to the empty string, do not overwrite. This way a user
+# could set ALLUXIO_RAM_FOLDER="" to avoid using ramdisk at all. The ${X-Y} syntax will return $X
+# unless X is UNSET (not just empty), in which case it returns Y.
+ALLUXIO_RAM_FOLDER=${ALLUXIO_RAM_FOLDER-${DEFAULT_RAM_FOLDER}}
+
 if [[ -n "${ALLUXIO_MASTER_ADDRESS}" ]]; then
   echo "ALLUXIO_MASTER_ADDRESS is deprecated since version 1.1 and will be remove in version 2.0."
   echo "Please use \"ALLUXIO_MASTER_HOSTNAME\" instead."
@@ -65,7 +78,6 @@ if [[ -n "${ALLUXIO_LOGS_DIR}" ]]; then
 fi
 
 if [[ -n "${ALLUXIO_RAM_FOLDER}" ]]; then
-  ALLUXIO_JAVA_OPTS+=" -Dalluxio.worker.tieredstore.level0.alias=MEM"
   ALLUXIO_JAVA_OPTS+=" -Dalluxio.worker.tieredstore.level0.dirs.path=${ALLUXIO_RAM_FOLDER}"
 fi