rc.zram

#!/bin/sh
#################################################################################################################################################
#                                                                                                                                               #
# Previous standard setting                                                                                                                     #
# SIZE=1024                                                                                                                                     #
# echo $SIZE*1024*1024 | bc > /sys/block/zram0/disksize                                                                                         #
# default 1GB                                                                                                                                   #
# Script to start zRam (Virtual Swap Compressed in RAM)                                                                                         #
# https://github.com/otzy007/enable-zRam-in-Slackware                                                                                           #
#                                                                                                                                               #
#################################################################################################################################################
#                                                                                                                                               #
# http://forum.linuxvillage.org/index.php?topic=92.0                                                                                            #
# https://sergioprado.org/economizando-memoria-com-o-zram/                                                                                      #
# http://www.linuxquestions.org/questions/linux-kernel-70/zram-compression-ratio-4175588385/                                                    #
# https://www.ibm.com/developerworks/community/blogs/752a690f-8e93-4948-b7a3-c060117e8665/entry/ative_a_compactacao_de_memoria_com_zram?lang=en #
#                                                                                                                                               #
# Jean Zonta                                                                                                                                    #
# Slackware 14.2 x64                                                                                                                            #
# Genéric Kernel 4.9.41                                                                                                                         #
# wiki.anon                                                                                                                                     #
# echo "}oqo4gtutF_gnuu4ius4hx" | perl -pe \ 's/(.)/chr(ord($1)-2*3)/ge'                                                                        #
#                                                                                                                                               #
# My added news                                                                                                                                 #
#                                                                                                                                               #
# echo 1G > /sys/block/zram0/disksize                                                                                                           #
# config                                                                                                                                        #
# fstab                                                                                                                                         #
#                                                                                                                                               #
#################################################################################################################################################

# Null
NULL=/dev/null

# Check for existence  /dev/zram0
ZRAM=$(ls -l /dev/zram0 | awk '{print $10}')

# Definition priority for RAM
PRIORITYRAM="vm.swappiness=5"

# Definition priority for ZRAM
PRIORITYZRAM="vm.swappiness=100"

# File sysctl.conf
SYSCTL=/etc/sysctl.conf

# Check for existence of parameter
SWAPPINESS=$( grep -ri "vm.swappiness" $SYSCTL)

# File fstab
FSTAB=/etc/fstab

# Check configured partition
STRZRAM=$( grep -ri "/dev/zram0" $FSTAB | awk '{print $1}')


# Start ZRAM
start()
{
 echo 2G > /sys/block/zram0/disksize
  mkswap /dev/zram0
 swapon -p 50 /dev/zram0
}

# Config Parameters
config()
{

if [[ $ZRAM < $NULL && ! -f $SYSCTL ]]; then
 touch $SYSCTL
  echo -e "# Top priority for RAM usage\n$PRIORITYRAM" >> $SYSCTL
   echo -e "\nArquivo $SYSCTL e $PRIORITYRAM Criada com sucesso ..!!!\n"

elif [[ $ZRAM > $NULL && ! -f $SYSCTL ]]; then
 touch $SYSCTL
  echo -e "# Top priority for ZRAM usage\n$PRIORITYZRAM" >> $SYSCTL
   echo -e "\nArquivo $SYSCTL e $PRIORITYZRAM Criada com sucesso ..!!!\n"

elif [[ $ZRAM < $NULL && $SWAPPINESS < $NULL ]]; then
 echo -e "# Top priority for RAM usage\n$PRIORITYRAM" >> $SYSCTL
  echo -e "\n$PRIORITYRAM Criada com sucesso ..!!!\n"

elif [[ $ZRAM > $NULL && $SWAPPINESS < $NULL ]]; then
 echo -e "# Top priority for ZRAM usage\n$PRIORITYZRAM" >> $SYSCTL
  echo -e "\n$PRIORITYZRAM Criada com sucesso ..!!!\n"

elif [[ $ZRAM < $NULL && $SWAPPINESS > $NULL && $SWAPPINESS != $PRIORITYRAM ]]; then
   MODIFICA=$(sed -i 's/# Top priority for ZRAM usage/# Top priority for RAM usage/g;s/'"^$SWAPPINESS"'/'"$PRIORITYRAM"'/g' $SYSCTL)
    echo -e "\n# Top priority for RAM usage\n$PRIORITYRAM\nModificada com sucesso ..!!!\n"

elif [[ $ZRAM > $NULL && $SWAPPINESS > $NULL && $SWAPPINESS != $PRIORITYZRAM ]]; then
  MODIFICA=$(sed -i 's/# Top priority for RAM usage/# Top priority for ZRAM usage/g;s/'"^$SWAPPINESS"'/'"$PRIORITYZRAM"'/g' $SYSCTL)
   echo -e "\n# Top priority for ZRAM usage\n$PRIORITYZRAM\nModificada com sucesso ..!!!\n"
    fi
}

# Config ZRAM fstab
fstab()
{
 if [[ $ZRAM < $NULL && $STRZRAM < $NULL ]]; then
  echo -e "\n# Top priority for $PRIORITYRAM configured\n"

 elif [[ $ZRAM > $NULL && $STRZRAM > $NULL ]]; then
  echo -e "\n# Top priority for $STRZRAM configured\n"

 elif [[ $ZRAM > $NULL && $STRZRAM < $NULL && $SWAPPINESS == $PRIORITYZRAM ]]; then
  cp $FSTAB $FSTAB.old
   echo "/dev/zram0       none             swap        sw,pri=50        0   0" > $FSTAB
    cat $FSTAB.old >> $FSTAB

  MODIFICA=$(sed -i 's/defaults/noatime,barrier=0,commit=60/g' $FSTAB)
   rm -rf $FSTAB.old
    cat $FSTAB
     echo -e "/dev/zram0 configured sucessfull\n"

 elif [[ $ZRAM < $NULL && $STRZRAM > $NULL && $SWAPPINESS == $PRIORITYRAM ]]; then
  RM=$(sed -i '1d' $FSTAB)
    cat $FSTAB
     echo -e "\n# Top priority for /dev/zram0 not supported\n$FSTAB reconfigured sucessfull\n"
 fi
}

# Stop ZRAM
stop()
{
  swapoff /dev/zram0
}

case "$1" in

  start)
    start
  ;;

 config)
   config
  ;;

  fstab)
    fstab
  ;;

  stop)
    stop
  ;;

  restart)
    echo 1 > /sys/block/zram0/reset
  ;;

  *)
  echo "Usage: $0 (start|config|fstab|stop|restart)"
esac