Posts with the category Arch Linux

Checking ECC RAM with Linux

Using dmidecode:

dmidecode -t memory | grep 'Physical Memory Array' -A7

Using ecc_check.c (source):

wget -O ecc_check.c
gcc ecc_check.c -o ecc_check

The program will output a few lines of text; of which only the values in the far-right column are relevant. The values in this column represent whether ECC...

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Improving the Speed of Software Raid on Linux (Read/Write/Resync)

Speeding up the write access of a RAID array

echo 32768 > /sys/block/md0/md/stripe_cache_size

Source: Stackoverflow

Speeding up RAID1 array rebuild


echo 50000 > /proc/sys/dev/raid/speed_limit_min
echo 200000 > /proc/sys/dev/raid/speed_limit_max

the resync speed went from 1M/sec to about 25M/sec:

cat /proc/mdstat

Personalities : [raid1]
md1 : active raid1 sdb3[0] sda3[1]

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Setting up Python venvs on Arch Linux ARM

Since Python 3.3 venv is a module found in the standard library of Python. It can replace virtualenv / virtualenvwrapper. Creating a virtual environment is as simple as this:

python3 -m venv ~/.pyvenv/iplogger-3.4
source ~/.pyvenv/iplogger-3.4/bin/activate
# I didn't need the step below, don't know when it is required:

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Hosted Raspberry Pi at PCExtreme – Reinstalled with Arch Linux ARM

This is a follow up post for that one: Hosted Raspberry Pi at PCExtreme – Reinstalled with Raspbian.

I crashed my original OS and asked the kind people at PCExtreme to reinstall my RPi. They did and here is what I did when I received the credentials for the newly...

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Setting up a Raspberry Pi with Auto-Timelapse Recording

This blog post is still in the makes, you can, however, already take advantage of the pretty content available so far.

  1. Install Arch Linux ARM on SD Card (get the image from here)
  2. Plug SD card into RPi, connect the Camera Module (see this) and power up the RPi
  3. SSH into...

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Enabling Wake on Lan on an Arch Linux Computer

ip addr
ethtool enp1s0f0
ethtool enp1s0f1
ethtool -s enp1s0f0 wol g
ethtool enp1s0f0

What the g or the other options mean is stated here (source):

p Wake on phy activity
u Wake on unicast messages
m Wake on multicast messages
b Wake on broadcast messages
a Wake on ARP
g Wake...

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Solving NAK DHCP Problems with the Fritz!BOX 7490 router

If you encounter problems like these:

dhcpcd[13577]: eth0: broadcasting for a lease
dhcpcd[13577]: eth0: offered from
dhcpcd[13577]: eth0: reject NAK via

Online you will find a lot of old threads suggesting things like commenting out the line require dhcp_server_identifier in the file dhcpcd.conf. Didn't help in my case.

This happened...

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Arch Linux – Deploying a Pure Python Web App

Deploying a web app written in Python is not always easy. Here are a couple of easy steps to get it done on Arch Linux. These steps are not a perfect tutorial if you want to go for high traffic sites. It is more about automating the start-up of the...

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Using the Raspberry Pi Camera Board on Arch Linux ARM

Update 2014-01-14: There is now a completely Python-based camera-interface for you to work with: picamera


Add /opt/vc/bin to your $PATH:

# To add /opt/vc/bin temporarily to your $PATH:

and set up your /boot/config.txt to contain the following:


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WiFi Adapter "Siemens Gigaset USB Adapter 54" on Arch Linux ARM / Raspberry Pi

I have the Siemens Gigaset USB Adapter 54 v2 with a Prism54 chipset. It has the USB vendor/product ID 083a:4521:

Bus 001 Device 008: ID 083a:4521 Accton Technology Corp. Siemens S30863-<span...

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Setting up my Raspberry Pi for Raspberry Pi colocation by PCextreme

Setting up my Raspberry Pi for Raspberry Pi colocation by PCextreme.

# Change the root password:
# Full system upgrade:
pacman -Syyu
## Extend the root partition as explained on
fdisk -c /dev/mmcblk0
#   p  d-2  n-p-2  w
# on a newer Arch...

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Fix Time on Arch Linux Systems (Run ntpd -s every hour using systemd)

My Raspberry Pi running Arch Linux didn't get the proper time on system startup and here is the solution I came up with to solve this problem:

Create the file /etc/systemd/system/fix-time.service:

Description=Set the time using NTP time servers

ExecStart=/usr/sbin/ntpd -s


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Start a Python Tool or Web App that uses Virtualenv on system startup using Systemd

I.e. deploying a tool or Python app using systemd.

I would recommend setting up the environment variables as well as activating the virtualenv in a Bash script and call that from systemd.

Working setup

Here is the bash script starting the web app after setting up the virtualenv. It's stored in /home/coltrims/MaxiGauge/


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Start AutoSSH on System Startup Using Systemd on Arch Linux

OK, here is how to start ssh on system startup (this is the content of the systemd .service configuration file /etc/systemd/system/autossh.service):

Description=AutoSSH service for a reverse tunnel from to localhost

ExecStart=/usr/bin/autossh -M 0 -q -N -o "ServerAliveInterval 60"...

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VLAN – on Ubuntu, Arch Linux and Mac OS X



sudo apt-get install vlan
sudo su -c 'echo "8021q" >> /etc/modules'
sudo modprobe 8021q

Usage and Configuration

# adding a vlan to a network interface:
ip link add link eth0 name eth0.10 type vlan id 10
# configuring the vlan:
ip addr add brd dev...

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WiFi-Stick Edimax EW-7811Un for the RaspberryPi (with Arch Linux ARM)

This is how it shows up in the kernel log / dmesg on Ubuntu:

[712886.216957] usb 1-1.2: new high-speed USB device number 5 using dwc_otg
[712886.318980] usb 1-1.2: New USB device found, idVendor=7392, idProduct=7811
[712886.319014] usb 1-1.2: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[712886.319034] usb 1-1.2: Product: 802.11n WLAN Adapter
[712886.319051] usb...

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Ethernet of Raspberry Pi Running ALARM Died Once

Two or three weeks ago my Arch Linux ARM based Raspberry Pi died. At least it wasn't accessible via Ethernet anymore. Here are the syslog details:

Nov  4 01:45:01 alarmpi -- MARK --
Nov  4...

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Raspberry Pi

Today my Raspberry Pi finally arrived! One of the projects I'm planning to use it for is out-of-band management for PCs.

This blog post will evolve as I'll discover interesting things to do with my RPi.

About the hardware:

Arch Linux Essentials

Here are some of the steps that are most essential...

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Installing Arch Linux On An Asus EEE PC 900 Netbook

I used the built-in SD card reader to install Arch Linux from an SD card. The Arch Linux Wiki holds quite a few comments on what to take care of on the EEE PC 900.

The next steps were:

  • I upgraded to Grub2 (Yes, Arch Linux still uses Grub...

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Setting Up A Log Host for Syslog

Let's suppose you have a device that has remote logging capabilities like the Switch TL-SG3210. In this case you may want to set up a machine on your local network to receive these log messages and store them permanently.

On Linux you have the choice between rsyslog and <a...

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Install ArchLinuxARM on the Seagate GoFlex Home

Attention! This is an advanced topic! Do not engage in any activity if you're not cool with the Linux command line and ready to do something to your GoFlex Home that Seagate did not...

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synergy and synergy+ (similar to x2x)


Installing synergy on Arch Linux (Arch Wiki entry):

sudo pacman -S synergy

Installing synergy on Mac OS X 10.10

brew install cmake qt
cd ~/Downloads
git clone
cd synergy
git checkout focus-fix-patch
./ conf -g2 --mac-sdk 10.10 --mac-identity Yosemite
./ build

Or use the nightly build:

Using it:

Create a config file...

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