Raspberry Pi optimization and tuning

Related docs:

• https://extremeshok.com/1081/raspberry-pi-raspbian-tuning-optimising-optimizing-for-reduced-memory-usage/

RaspberryPi running Raspbian

username: pi
password: raspberry

This will reduce the memory consumption by 10MB, however you will be sacrificing: ssh portforwarding and ssh logging.

 apt-get install dropbear openssh-client

Stop OpenSSH server you will not loose your current SSH connection, if you are connected via ssh

 /etc/init.d/ssh stop

Enable dropbear to start at boot-time

 sed -i 's/NO_START=1/NO_START=0/g' /etc/default/dropbear

optional: prevent root logins

 sed -i 's/DROPBEAR_EXTRA_ARGS=/DROPBEAR_EXTRA_ARGS="-w"/g' /etc/default/dropbear

optional: prevent password logins

 sed -i 's/DROPBEAR_EXTRA_ARGS=/DROPBEAR_EXTRA_ARGS="-s"/g' /etc/default/dropbear

optional: prevent password logins for root

 sed -i 's/DROPBEAR_EXTRA_ARGS=/DROPBEAR_EXTRA_ARGS="-g"/g' /etc/default/dropbear

optional: prevent root logins and prevent password logins

 sed -i 's/DROPBEAR_EXTRA_ARGS=/DROPBEAR_EXTRA_ARGS="-w -s"/g' /etc/default/dropbear

optional: change the listening port from 22 to 2222

 sed -i 's/DROPBEAR_PORT=22/DROPBEAR_PORT=2222/g' /etc/default/dropbear

Start Dropbear

 /etc/init.d/dropbear start

Test Make sure you can connect to the server over ssh (using an ssh client). Disable OpenSSH, but allow it to be used for SSH / SFTP

<h2>Remove the extra tty / getty's | Save: +3.5 MB RAM</h2> tty2-tty6 will be disabled. We are keeping tty1 for console, unless you choose to disable it. <pre class=“lang:sh decode:true”>sed -i '/[2-6]:23:respawn:\/sbin\/getty 38400 tty[2-6]/s%^%#%g' /etc/inittab 1 2 3

<h2>Remove the extra tty / getty's | Save: +3.5 MB RAM</h2> tty2-tty6 will be disabled. We are keeping tty1 for console, unless you choose to disable it. <pre class=“lang:sh decode:true”>sed -i '/[2-6]:23:respawn:\/sbin\/getty 38400 tty[2-6]/s%^%#%g' /etc/inittab

optional: disable getty on the Raspberry Pi serial line Shell sed -i '/T0:23:respawn:\/sbin\/getty -L ttyAMA0 115200 vt100/s%^%#%g' /etc/inittab 1

sed -i '/T0:23:respawn:\/sbin\/getty -L ttyAMA0 115200 vt100/s%^%#%g' /etc/inittab Replace Bash shell with Dash shell | Save: +1 MB RAM

Replacing Bash with Dash will increase the system’s overall performance ie. speed up the system boot, reduce disk space, use fewer libraries (save memory) and is more reliable: Dash is an acronym for Debian Almquist shell (dash). It is a Unix and Linux shell which is much smaller than bash but still aiming at POSIX-compliancy. dash is a POSIX-compliant implementation of /bin/sh that aims to be as small as possible. dash is a direct descendant of the NetBSD version of ash (the Almquist SHell), ported to Linux in early 1997. It was renamed to dash in 2002. Shell dpkg-reconfigure dash 1

dpkg-reconfigure dash

  Use dash as the default system shell (/bin/sh)? Yes

Enable a 512MB swapfile

Customize the size of the swap file, 512MB recommended. Shell echo “CONF_SWAPSIZE=512” > /etc/dphys-swapfile 1

echo “CONF_SWAPSIZE=512” > /etc/dphys-swapfile

Initialize the swapfile Shell dphys-swapfile setup 1

dphys-swapfile setup

Start/enable the swapfile Shell dphys-swapfile swapon 1

dphys-swapfile swapon Enable better usage of the swap

Default swappiness is 1, we will change this value to 10, which will allow for better memory usage at the expense of more swap usage. note: this could reduce the life of your sdcard. Shell sed -i 's/vm.swappiness=1/vm.swappiness=10/g' /etc/sysctl.conf 1

sed -i 's/vm.swappiness=1/vm.swappiness=10/g' /etc/sysctl.conf

Purge cached block devices before cached filesystem entries Shell echo 'vm.vfs_cache_pressure=50' » /etc/sysctl.conf 1

echo 'vm.vfs_cache_pressure=50' » /etc/sysctl.conf Optional: Enable Preload to speed up load times | only recommended for desktop usage

Note: this will increase memory usage, recommended for desktop to increase overall responsiveness. Do NOT enable for servers. Shell apt-get install -y preload 1

apt-get install -y preload Shell sed -i 's/sortstrategy = 3/sortstrategy = 0/g' /etc/preload.conf 1

sed -i 's/sortstrategy = 3/sortstrategy = 0/g' /etc/preload.conf

Reboot Shell shutdown -r now 1

shutdown -r now Optimize / mount Shell sed -i 's/defaults,noatime/defaults,noatime,nodiratime/g' /etc/fstab 1

sed -i 's/defaults,noatime/defaults,noatime,nodiratime/g' /etc/fstab Disable IPv6

Most users will not need ipv6 support and if you are only using a local there is no need. Disable it to save the resources and speed up networking. Shell echo “net.ipv6.conf.all.disable_ipv6=1” > /etc/sysctl.d/disableipv6.conf 1

echo “net.ipv6.conf.all.disable_ipv6=1” > /etc/sysctl.d/disableipv6.conf

Disable the kernel module Shell echo 'blacklist ipv6' » /etc/modprobe.d/blacklist 1

echo 'blacklist ipv6' » /etc/modprobe.d/blacklist

Remove IPv6 hosts Shell sed -i '/::/s%^%#%g' /etc/hosts 1

sed -i '/::/s%^%#%g' /etc/hosts

Reboot Shell shutdown -r now 1

shutdown -r now Overclock cpu, sdram and gpu core without increasing voltage

Overclocking is now Officially Supported.

  “None” “700MHz ARM, 250MHz core, 400MHz SDRAM, 0 overvolt”
  “Modest” “800MHz ARM, 300MHz core, 400MHz SDRAM, 0 overvolt”
  “Medium” “900MHz ARM, 333MHz core, 450MHz SDRAM, 2 overvolt”
  “High” “950MHz ARM, 450MHz core, 450MHz SDRAM, 6 overvolt”
  “Turbo” “1000MHz ARM, 500MHz core, 500MHz SDRAM, 6 overvolt”

Select one of the following options:

800Mhz permanently: The settings below are safe for all Raspberry Pi’s Shell echo -e “arm_freq=850\nsdram_freq=450\ncore_freq=350\nforce_turbo=1” » /boot/config.txt 1

echo -e “arm_freq=850\nsdram_freq=450\ncore_freq=350\nforce_turbo=1” » /boot/config.txt OR

850Mhz permanently: The settings below are only to be used if you have heatsinks installed Shell echo -e “arm_freq=950\nsdram_freq=500\ncore_freq=450\nforce_turbo=1” » /boot/config.txt 1

echo -e “arm_freq=950\nsdram_freq=500\ncore_freq=450\nforce_turbo=1” » /boot/config.txt OR

700Mhz-1000Mhz dynamic: Scales the cpu frequency according to the load Shell echo -e “force_turbo=0” » /boot/config.txt 1

echo -e “force_turbo=0” » /boot/config.txt

Reboot Shell shutdown -r now 1

shutdown -r now Replace Deadline Scheduler with NOOP Scheduler

NOOP scheduler is best used with solid state devices such as flash memory. Shell sed -i 's/deadline/noop/g' /boot/cmdline.txt 1

sed -i 's/deadline/noop/g' /boot/cmdline.txt

Reboot Shell shutdown -r now 1

shutdown -r now Replace rsyslogd with inetutils-syslogd and remove useless logs

Reduce memory and cpu usage. We just need a simple vanilla syslogd. Also there is no need to log so many files. Just dump them into /var/log/(cron/mail/messages)

remove rsystlog Shell apt-get -y remove –purge rsyslog 1

apt-get -y remove –purge rsyslog

install syslogd Shell apt-get -y install inetutils-syslogd 1

apt-get -y install inetutils-syslogd

Create a vanilla syslogd setup Stop syslogd Shell service inetutils-syslogd stop 1

service inetutils-syslogd stop

Remove old logs Shell for file in /var/log/*.log /var/log/mail.* /var/log/debug /var/log/syslog; do [ -f “$file” ] && rm -f “$file”; done for dir in fsck news; do [ -d “/var/log/$dir” ] && rm -rf “/var/log/$dir”; done 1 2

for file in /var/log/*.log /var/log/mail.* /var/log/debug /var/log/syslog; do [ -f “$file” ] && rm -f “$file”; done for dir in fsck news; do [ -d “/var/log/$dir” ] && rm -rf “/var/log/$dir”; done

Create syslog.conf Shell echo -e “*.*;mail.none;cron.none\t -/var/log/messages\ncron.*\t -/var/log/cron\nmail.*\t -/var/log/mail” > /etc/syslog.conf 1

echo -e “*.*;mail.none;cron.none\t -/var/log/messages\ncron.*\t -/var/log/cron\nmail.*\t -/var/log/mail” > /etc/syslog.conf

Configure logrotate Shell mkdir -p /etc/logrotate.d echo -e “/var/log/cron\n/var/log/mail\n/var/log/messages {\n\trotate 4\n\tweekly\n\tmissingok\n\tnotifempty\n\tcompress\n\tsharedscripts\n\tpostrotate\n\t/etc/init.d/inetutils-syslogd reload >/dev/null\n\tendscript\n}” > /etc/logrotate.d/inetutils-syslogd 1 2

mkdir -p /etc/logrotate.d echo -e “/var/log/cron\n/var/log/mail\n/var/log/messages {\n\trotate 4\n\tweekly\n\tmissingok\n\tnotifempty\n\tcompress\n\tsharedscripts\n\tpostrotate\n\t/etc/init.d/inetutils-syslogd reload >/dev/null\n\tendscript\n}” > /etc/logrotate.d/inetutils-syslogd

Start syslogd Shell service inetutils-syslogd start 1

service inetutils-syslogd start

[/social-locker] Set a static IP and remove DHCP-Client

Reduces CPU and memory. Create a backup config Shell cp -f /etc/network/interfaces /etc/network/interfaces.dhcp-backup 1

cp -f /etc/network/interfaces /etc/network/interfaces.dhcp-backup

Edit file: /etc/network/interfaces replace

  iface eth0 inet dhcp

with

  iface eth0 inet static
  #set your static IP below
  address 192.168.1.107

  #set your default gateway IP here
  gateway 192.168.1.1

  netmask 255.255.255.0
  network 192.168.1.0
  broadcast 192.168.1.255

Reboot Shell shutdown -r now 1

shutdown -r now