Raspberry PI 512 MB RAM – memory split

New Raspberry PI 512 MB of RAM possible memory splits:


arm128_start.elf
arm192_start.elf
arm224_start.elf
arm240_start.elf
arm256_start.elf
arm384_start.elf
arm448_start.elf
arm496_start.elf


Raspberry Pi Debian – How to change swap size

sudo nano /etc/dphys-swapfile
sudo dphys-swapfile setup
sudo dphys-swapfile swapon

Linux – how to check which process is using most memory

ps -elf|awk '{print $10, $3, $4, $15, $16}'|sort -nr|head

Raspberry PI kiosk mode with Chromium.

1. Install chromium, x11-xserver-utils and unclutter

sudo apt-get update && apt-get upgrade -y
sudo apt-get install chromium x11-xserver-utils unclutter

2. We need to prevent screen from going blank and disable screen saver.
– edit /etc/xdg/lxsession/LXDE/autostart and comment # screen saver line and add those lines:

@xset s off
@xset -dpms
@xset s noblank
@chromium --kiosk --incognito http://some.web.

Done.

Slow Wifi, Problem Solved- Ubuntu 10.04, 10.10

1. The Debian Avahi (nss-mdns) Bug
There is a known bug doing the rounds in Debian based distros, this includes Ubuntu.
The problem is in the nsswitch.conf file where wins mdns causes a slowdown of DNS resolution on some machines.
https://bugs.launchpad.net/ubuntu/+s…ahi/+bug/94940
A simple workaround for this problem is to remove mdns4_minimal entry from the nsswitch.conf file, or change mdns4_minimal to just mdns4 (whichever works best for you):
Edit this file- /etc/nsswitch.conf
Scroll down to the entry which says:
hosts: files dns wins mdns4_minimal
and delete the mdns4_minimal entry. (I removed wins as well), s it looks like this:
hosts: files dns
2. Check your DNS in resolv.conf
You should only have two entries (usually) which are your Internet Service Provider’s DNS servers.
Check and/or edit your dns servers:
gksudo scite /etc/resolv.conf
It should look something like this:
search my.isp.com
nameserver 4.4.2.2
nameserver 4.4.2.4
You may have an extra IP address there, possibly your router (192.168.1.1), and if you haven’t got dns servers configured in your router config, this may cause a problem/slowdown as well. EG:
search my.isp.com
nameserver 192.168.1.1
nameserver 4.4.2.2
nameserver 4.4.2.4
Just remove the first one and leave the two ISP DNS server IP’s.

original link http://ubuntuforums.org/showthread.php?t=1487039&page=2

How change WiFi Rates – Linux

sudo iwconfig wlan0 rate 54M

Available rates: 1, 2, 6, 9, 12, 18, 24, 36, 48 and 54

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Useful configuration tools

gconf-editor – gnome configuration tool
rcconf – system services configuration tool

Mounting NTFS partition /etc/fstab

1. Open a Terminal and type

gksudo gedit /etc/fstab

2. Add this line

/dev/sdaX /media/sdaX ntfs-3g user,defaults 0 0

X – depend on your partition layout. To check partition layout type:

sudo fdisk -l

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How To Restore Nautilus Address Bar or Location Bar in Ubuntu 10.04

1 Open terminal or press Alt+F2

gconf-editor

2. locate this

/apps/nautilus/preferences/always_use_location_entry

and tick a box.

Source: http://ubuntuforums.org/showthread.php?t=77346

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xorg.conf – when Ubuntu is not detecting your monitor correctly

1. touch /etc/X11/xorg.conf

2. open file and paste this:

Section "Monitor"
Identifier "Monitor1"
Vendorname "Generic LCD"
Horizsync 31.5-48.0
Vertrefresh 56.0-65.0
EndSection

Section "Screen"
Identifier "Screen1"
Monitor "Monitor1"
Subsection "Display"
Modes "1024x768" "800x600"
EndSubsection
EndSection

3. save & restart xorg

Terminal programs – tools, games, eye candy

tools:

htop, nload, wavemon, mtr

games:

tetris, greed, ninvaders

eye candy:

cmatrix

iptables IP blocking

to make a new rule:
sudo iptables -I INPUT -s 11.11.11.11 -j DROP

—

to delete a rule:
sudo iptables -D INPUT x
x=rule number

—

to list iptables rules:
iptables -L

right click image resizer

sudo aptitude install nautilus-image-converter

right click on a picture
– resize
– rotate

What is swappiness and how do I change it?

The swappiness parameter controls the tendency of the kernel to move processes out of physical memory and onto the swap disk. Because disks are much slower than RAM, this can lead to slower response times for system and applications if processes are too aggressively moved out of memory.

• swappiness can have a value of between 0 and 100
• swappiness=0 tells the kernel to avoid swapping processes out of physical memory for as long as possible
• swappiness=100 tells the kernel to aggressively swap processes out of physical memory and move them to swap cache

The default setting in Ubuntu is swappiness=60. Reducing the default value of swappiness will probably improve overall performance for a typical Ubuntu desktop installation. A value of swappiness=10 is recommended, but feel free to experiment. Note: Ubuntu server installations have different performance requirements to desktop systems, and the default value of 60 is likely more suitable.

To check the swappiness value

cat /proc/sys/vm/swappiness

To change the swappiness value A temporary change (lost on reboot) with a swappiness value of 10 can be made with

sudo sysctl vm.swappiness=10

To make a change permanent, edit the configuration file with your favorite editor:

gksudo gedit /etc/sysctl.conf

Search for vm.swappiness and change its value as desired. If vm.swappiness does not exist, add it to the end of the file like so:

vm.swappiness=10

Save the file and reboot.

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original article https://help.ubuntu.com/community/SwapFaq

Ubuntu 9.10 Vodafone Pay As You Go (UK)

Vodafone Pay As You Go (UK) config
APN is pp.internet should be ppbundle.internet
user / password: web / web