Login as root
All the items will need to be done as the root user. Make sure you become root after every restart.
Shell
sudo su
free -htl
Will return something like this
total used free shared buffers cached Mem: 215M 46M 168M OB 8.4M 21M Low:215M 46M 168M High: OB OB OB -/+ buffers/cache: 16M 199M Swap: 99M OB 99M Total: 31 5M 46M 268M
Replacing OpenSSH with Dropbear | Save: +10MB RAM
This will reduce the memory consumption by 10MB, however you will be sacrificing: ssh portforwarding and ssh
logging.
install dropbear
openssh-client is installed to provide SCP support for the dropbear server
Shell
apt-get install dropbear openssh-client
Stop OpenSSH server
you will not loose your current SSH connection, if you are connected via ssh
Shell
/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
Start Dropbear
/etc/init.d/dropbear start
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
update-rc.d ssh disable
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.
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.
echo "CONF_SWAPSIZE=512" > /etc/dphys-swapfile
Initialize the swapfile
dphys-swapfile setup
Start/enable the swapfile
dphys-swapfile swapon
Enable better usage of the swap
Default swappiness is 1 , we will change this value to 1 0, which will allow for better memory usage at the expense of
more swap usage, note: this could reduce the life of your sdcard.
sed -i 's/vm.swappiness=1/vm.swappiness=10/g' /etc/sysctl.conf
Purge cached block devices before cached filesystem entries
echo 'vm.vfs_cache_pressure=50' » /etc/sysctl.conf
Optimize / mount
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.
echo "net.ipv6.conf.all.disable_ipv6=1" > /etc/sysctl.d/disableipv6.conf
Disable the kernel module
echo 'blacklist ipv6' » /etc/modprobe.d/blacklist
Remove IPv6 hosts
sed -i 7::/s% A %#%g' /etc/hosts
Reboot
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" "900MHzARM, 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
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
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
1 echo -e "force_turbo=0" » /boot/config.txt
Reboot
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
Reboot
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
apt-get -y remove --purge rsyslog
install syslogd
apt-get -y install inetutils-syslogd
Create a vanilla syslogd setup
Stop syslogd
service inetutils-syslogd stop
Remove old logs
/var/log/Mog /var/log/mail.* /var/log/debug /var/log/syslog; do [ -f "$file" ] && rm -f "$file"; done
[ -d 7var/log/$dir" ] && rm -rf "/var/log/$dir"; done
Create syslog.conf
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
mkdir -p /etc/logrotate.d
echo -e 7var/log/cron\n/var/log/mail\n/var/log/messages {\n\trotate
\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
service inetutils-syslogd start
Set a static IP and remove DHCP-Client
Reduces CPU and memory.
Create a backup config
cp -f /etc/network/interfaces /etc/network/interfaces. dhcp-backup
Edit file: /etc/network/interfaces
replace
iface ethO inet dhcp
with
iface ethO 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
shutdown -r now
