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Revision 2 as of 2014-03-26 23:23:21
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Editor: ?AntonioGalea
Comment:
Revision 12 as of 2016-09-02 12:30:37
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Editor: ?MertDirik
Comment: fix # of CPUs
Deletions are marked like this. Additions are marked like this.
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#language en
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 * http://en.wikipedia.org/wiki/Zram  * WikiPedia:Zram
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Copy the following script to /etc/init.d/zram: Copy the following script to ''/etc/init.d/zram'':
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## /etc/init.d/zram
#!/bin/bash
#!sh
#!/bin/sh
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# Description: Use compressed RAM as in-memory swap  # Description: Use compressed RAM as in-memory swap
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# Thanks to Przemysław Tomczyk for suggesting swapoff parallelization
# Distributed under the GPL version 3 or above, see terms at
# https://gnu.org/licenses/gpl-3.0.txt
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CPUS=`grep -c processor /proc/cpuinfo` CPUS=`nproc`
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      echo $SIZE > /sys/block/zram$i/disksize        echo $SIZE > /sys/block/zram$i/disksize
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      swapoff /dev/zram$i       swapoff /dev/zram$i && echo "disabled disk $n of $CPUS" &
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    wait
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then instruct you system to start it at boot time, with the command then you may have to make the script executable:
{{{
chmod +x /etc/init.d/zram
}}}

then instruct your system to start it at boot time, with the command
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== NB! ==

For the version with the systemd should be used package [[http://packages.ubuntu.com/vivid/zram-config|Ubuntu zram-config 0.3]] and newer.

zram (previously called compcache) can create RAM based block devices. It is an experimental (staging) module of the Linux kernel since 3.2.

Background information

Startup script

Copy the following script to /etc/init.d/zram:

#!/bin/sh
### BEGIN INIT INFO
# Provides:          zram
# Required-Start:    $local_fs
# Required-Stop:     $local_fs
# Default-Start:     S
# Default-Stop:      0 1 6
# Short-Description: Use compressed RAM as in-memory swap
# Description:       Use compressed RAM as in-memory swap
### END INIT INFO

# Author: Antonio Galea <antonio.galea@gmail.com>
# Thanks to Przemysław Tomczyk for suggesting swapoff parallelization
# Distributed under the GPL version 3 or above, see terms at
#      https://gnu.org/licenses/gpl-3.0.txt

FRACTION=75

MEMORY=`perl -ne'/^MemTotal:\s+(\d+)/ && print $1*1024;' < /proc/meminfo`
CPUS=`nproc`
SIZE=$(( MEMORY * FRACTION / 100 / CPUS ))

case "$1" in
  "start")
    param=`modinfo zram|grep num_devices|cut -f2 -d:|tr -d ' '`
    modprobe zram $param=$CPUS
    for n in `seq $CPUS`; do
      i=$((n - 1))
      echo $SIZE > /sys/block/zram$i/disksize
      mkswap /dev/zram$i
      swapon /dev/zram$i -p 10
    done
    ;;
  "stop")
    for n in `seq $CPUS`; do
      i=$((n - 1))
      swapoff /dev/zram$i && echo "disabled disk $n of $CPUS" &
    done
    wait
    sleep .5
    modprobe -r zram
    ;;
  *)
    echo "Usage: `basename $0` (start | stop)"
    exit 1
    ;;
esac

then you may have to make the script executable:

chmod +x /etc/init.d/zram

then instruct your system to start it at boot time, with the command

  insserv zram

NB!

For the version with the systemd should be used package Ubuntu zram-config 0.3 and newer.