disable_thp.sh

#!/bin/bash
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#
# Copyright Clairvoyant 2015

# Function to discover basic OS details.
discover_os() {
  if command -v lsb_release >/dev/null; then
    # CentOS, Ubuntu
    OS=`lsb_release -is`
    # 7.2.1511, 14.04
    OSVER=`lsb_release -rs`
    # 7, 14
    OSREL=`echo $OSVER | awk -F. '{print $1}'`
    # trusty, wheezy, Final
    OSNAME=`lsb_release -cs`
  else
    if [ -f /etc/redhat-release ]; then
      if [ -f /etc/centos-release ]; then
        OS=CentOS
      else
        OS=RedHatEnterpriseServer
      fi
      OSVER=`rpm -qf /etc/redhat-release --qf="%{VERSION}.%{RELEASE}\n"`
      OSREL=`rpm -qf /etc/redhat-release --qf="%{VERSION}\n" | awk -F. '{print $1}'`
    fi
  fi
}

echo "********************************************************************************"
echo "*** $(basename $0)"
echo "********************************************************************************"
# Check to see if we are on a supported OS.
discover_os
if [ "$OS" != RedHatEnterpriseServer -a "$OS" != CentOS -a "$OS" != Debian -a "$OS" != Ubuntu ]; then
  echo "ERROR: Unsupported OS."
  exit 3
fi

echo "Disabling Transparent Huge Pages..."
if [ "$OS" == RedHatEnterpriseServer -o "$OS" == CentOS ]; then
  if [ $OSREL == 6 ]; then
    echo never >/sys/kernel/mm/transparent_hugepage/defrag
    echo never >/sys/kernel/mm/transparent_hugepage/enabled
    sed -i '/transparent_hugepage/d' /etc/rc.d/rc.local
    echo 'echo never >/sys/kernel/mm/transparent_hugepage/defrag' >>/etc/rc.d/rc.local
    echo 'echo never >/sys/kernel/mm/transparent_hugepage/enabled' >>/etc/rc.d/rc.local
  else
    # http://www.certdepot.net/rhel7-rc-local-service/
    sed -i '/transparent_hugepage/d' /etc/rc.d/rc.local
    echo 'echo never >/sys/kernel/mm/transparent_hugepage/defrag' >>/etc/rc.d/rc.local
    echo 'echo never >/sys/kernel/mm/transparent_hugepage/enabled' >>/etc/rc.d/rc.local
    chmod +x /etc/rc.d/rc.local
    systemctl start rc-local
  fi
elif [ "$OS" == Debian -o "$OS" == Ubuntu ]; then
  echo never >/sys/kernel/mm/transparent_hugepage/defrag
  echo never >/sys/kernel/mm/transparent_hugepage/enabled
  sed -e '/transparent_hugepage/d' \
      -e '/^exit 0/i \
echo never >/sys/kernel/mm/transparent_hugepage/defrag\
echo never >/sys/kernel/mm/transparent_hugepage/enabled' \
      -i /etc/rc.local
fi