Archives/Shop 3.0/Ctag computer notes

Archival Notice
This page is archived and may not be up to date.

1 Overview
- 1.1 Naming Schemes
2 General Program Notes
- 2.1 SVG path to OpenSCAD
3 General Archlinux Notes
- 3.1 Systemctl Timed Out
- 3.2 GPG and Duplicity
4 bns-anarch
5 bns-kharselim
6 Coyote Raspberry Pi's
- 6.1 Wireless AP
7 Backups
- 7.1 Noncritical
8 RPi Notes
- 8.1 Failed to start Load Kernel Modules
9 Debian Notes

Overview

My notes for installing and maintaining GNU/Linux instances, working with personal computer hardware, etc.

Naming Schemes

bns stands for Bero Network Service; it's a cute way to reference computers I personally own that I came up with in middle school.

All of my real computers (loosely defined as ones running GNU/Linux) are named after fictional spacecraft. I do this because I think it sounds nice, like USS-Alabama is the naming scheme for United States Ships. The one exception to this rule is my main desktop, which isn't named after anything else.

General Program Notes

SVG path to OpenSCAD

Make everything a path. Go to extensions > modify path > flatten bezier. Save as DXG R14.

Import in openscad and be done.

Also covers the warning "WARNING: Unsupported DXF Entity `SPLINE'"

http://www.inkscapeforum.com/viewtopic.php?t=12841

General Archlinux Notes

Systemctl Timed Out

Error:

$systemctl enable whatever.service
[...]
Failed to execute operation: Connection timed out

Cause: lvm2 is broken.

Fix: I just uninstalled lvm2 on this machine, as it was unneeded.

https://github.com/systemd/systemd/issues/3353

GPG and Duplicity

If you get an error about not being able to use the signing keys or ioctl, make sure you've got something set up in .bashrc like this:

# For duplicity
export GPG_TTY=$(tty)
echo "UPDATESTARTUPTTY" | gpg-connect-agent > /dev/null 2&>1

For some reason the pinentry dialog won't show up without it.

https://www.gnupg.org/documentation/manuals/gnupg/Invoking-GPG_002dAGENT.html

bns-anarch

2013 Installation Notes

Notes copied as they were found from an old piece of paper.

Install date: 15-12-2013

Followed Beginner Guide on archwiki.
Network: Default dhcpcd.service, IP set by MAC on router.
Disk:
- 1Gig 'ef' (ef00) partition for /boot
- 110Gig ext4
NFS:
- Installed nfs-utils
- Enable rpc-statd.service
- fstab won't mount on boot without x-systemd.automount flag
- rpc-gssd.service totally kills NFS!
Yeti USB:
- Must not be plugged into USB 3.0 port!
- To list modules: 'aplay -l'
- Set Yeti as default device, edit /etc/modprobe.d/alsa.conf

options snd slots=snd_usb_audio,snd_hda_intel
options snd_usb_audio index=0
options snd_hda_intel index=1

nVidia Driver:
- Packages: nvidia, nvidia_libgl, nvidia-utils, opencl-nvidia, nvidia-cg-*, libcl, lib32-opencl-nvidia, libvdpau
- libvdpau is needed for 'flashplugin' and lib32-flashplugin
- Setup xorg.conf for a new X screen on each monitor.
BIOS
- Turn on IOMMU, turn off XHCI
VPN
- /etc/dhcpcd.conf: nooption domain_name_servers, domain_name
- Add DNS to /etc/resolv.conf.head

Thinkpad fan control

I haven't found a good solution for fan control on the x120e, but tpfanco-svn from the AUR works reasonably well. Both lm-sensors and fancontrol were totally awful to configure/use.

Configuration on ArchWiki

youtube-dl stacktrace

youtube-dl fails after I made the python symlinks sane again.

to fix it, edit /usr/bin/youtube-dl and change the first line to use /usr/bin/python3.4

HP J4580 Unrecognized

Symptoms: HP printer that's only good for flatbed scanning is suddenly unrecognized even though hplip is installed.

Steps to reproduce: Try scanning in homework with less than half an hour left on the clock.

It fucking works, just uncomment 'hpaio' at the end of /etc/sane.d/dll.conf

Slic3r HTTPS API

Received this error in Slic3r when connecting to octoprint via HTTPS only:

I wasn't able to connect to OctoPrint (501 Protocol scheme 'https' is not supported (LWP::Protocol::https not installed)). Check hostname and OctoPrint version (at least 1.1.0 is required).

Solution: install perl-lwp-protocol-https from the official repos.

ReText

To make the icons appear, you have to set the icon theme name in ReText.conf

http://www.svenbit.com/2012/05/fix-missing-toolbar-icon-in-retext/

MATLAB

To install, I had to go get the following packages:

lib32-libxmu
lib32-libxp
lib32-libxtst
lib32-ncurses5-compat-libs
bin32-jre6
wmname

/usr/share/applications/matlab.desktop

#!/usr/bin/env xdg-open
[Desktop Entry]
Type=Application
Icon=/usr/share/icons/matlab.png
Name=MATLAB
Comment=Start MATLAB - The Language of Technical Computing
Exec=cd /home/berocs/Documents/uah && wmname LG3D && env MATLAB_JAVA=/usr/lib32/jvm/java32-6-jre/jre matlab -desktop -nosplash -glnx86
Categories=Development;
MimeType=text/x-matlab;

The 'cd /home/berocs/Documents/uah' portion of the .desktop file makes MATLAB use my uah directory as its default, which makes navigating class project files much easier.

I recently had to use 'fdatool' for a class, and the sub-windows wouldn't render any contents. To fix this I migrated from jre8 to jre6.

Licensing

Matlab checks the mac address of "eth0" for license validation. There isn't an eth0 on Archlinux, so we'll have to spoof it.

Manually

To create a dummy0 device, load the 'dummy' module

ip a # No dummy0 device
sudo modprobe dummy
ip a # dummy0@NONE should exist

Next, we need to turn the dummy device into a fake eth0 and assign it the MAC address that matlab is looking for.

sudo ip link set dev dummy0 name eth0
sudo ip link set dev eth0 address e8:9a:8f:00:00:00

Automatically

Edit /etc/modules-load.d/dummy.conf to have

dummy

Now the dummy0 device will appear on boot.

Next we need to create a systemd service that will assign the eth0 name to the dummy device.

/etc/systemd/system/matlab.licensing.service

[Unit]
Description=Dummy network interface for MATLAB
Requires=systemd-modules-load.service
After=systemd-modules-load.service

[Service]
Type=oneshot
ExecStart=/usr/bin/ip link set dev dummy0 name eth0
ExecStart=/usr/bin/ip link set dev eth0 address e8:9a:8f:8d:79:84

[Install]
WantedBy=multi-user.target

Steam

Upon receiving the error

libGL error: unable to load driver: nouveau_dri.so

I found [1] and ran the command

rm ~/.local/share/Steam/ubuntu12_32/steam-runtime/i386/usr/lib/i386-linux-gnu/libstdc++.so.6

to solve the problem.

Battle of Wesnoth

From the installation package:

==> If you experience sound problems try setting your SDL_AUDIODRIVER environment variable to "dma"
==> eg. export SDL_AUDIODRIVER="dma" ; wesnoth
==> If "dma" doesn't work,other options are: dsp,alsa,artsc,esd,nas try to find the right output.

bns-kharselim

Installing Archlinux

Migrating from Debian Testing Dec 2014.

Migration notes:

Backing up rootfs to bns-readynas

- Script in archtools

Backing up home to 16G flash drive

- rsync -avz . /media/berocs/DTM30/

- Scratch the above, flash drive is 16G, need 33G. rsync-ing to nfs:/bkup.

Fixing the Thinklight

Ever since I bought this laptop, the Thinklight hasn't worked, and I just assumed it was a casualty of having libreboot on the system. Today, however, an irc member on #libreboot pointed me to a German forum post which discussed a hardware issue and solution with X200 Thinklights.

I set out to make the same changes to my X200, and found that it worked! My Thinklight now operates nominally, with two tiny wires run behind the ribbon cable and soldered to the connector and LED.

1. Disassemble the laptop and remove screen.
2. Find a nice workspace and solder iron. A microscope really helps.
3. The 11th and 12th traces are the ones that need to be soldered.
4. Each trace lines up left/right with the pads on the LED.
5. I routed the wires along the same connector as the ribbon cable.
6. The left connector trace needs to be bridged to the left LED pad, same for the right side.
7. Taped and tidied with kapton tape.
8. It works!
9. Well that was easy.

Resurfacing the keyboard

--> This process isn't permanent. For me, the new surface lasted about two months before wearing away.

This laptop isn't exactly new, and one of the most obvious signs of wear has been the "slick spots" where the texturing on individual keys has worn down. Once again, an irc user came to my aid, and informed me of this German wiki page, where the issue is tackled.

I.. can't read German, so the page was loosely translated mechanically, and I tried to put the pieces together. Here's what I got:

Clean the keyboard really well (dish soap, microfiber cloth, isopropyl)
Get some clear coat matte finish wheel spraypaint (duplicolor brand)
Paint the keyboard?

I wound up buying "Dupli-Color wheel matte clearcoat" which is product "HWP106"

I only washed the keyboard with a toothbrush and hand soap, drying with a microfiber towel. I didn't clean the keyboard as well as I should have, it would get perfectly clean, and then immediately some dust would settle on it. Oh well, the result still turned out OK.

Pictures:

Remove keyboard
Clean keyboard
Spray paint booth
Tape off and set up
First layer
Third layer
Reinstalled

I added layers until the glossy spots were just barely visible, with 10 minutes between layers.

Now to find out how well it holds up!

Firefox doesn't play nice with GTK Themes

What's happening is that lxappearance sets the gtk2 theme, and firefox uses the gtk3 theme. You have to look at both.

GTK2 is ~/.gtkrc-2.0

GTK3 is ~/.config/gtk-3.0/

Using a Brother DS-620

Forum post read it all the way through.

Libreoffice keeps segfaulting

Libreoffice would crash almost as soon as it lost focus as the main window in i3.

to fix this I had to edit the version of gtk being used in some configuration files.

https://bbs.archlinux.org/viewtopic.php?id=202672

qtcreator crash on help

Delete the helpcollection folder and .qhc file.

https://bugreports.qt.io/browse/QTCREATORBUG-14165

r600 driver on steam

Error:

[berocs@bns-kharselim ~]$ env LIBGL_DEBUG=verbose steam
Running Steam on arch rolling 64-bit
STEAM_RUNTIME is enabled automatically
Installing breakpad exception handler for appid(steam)/version(0)
libGL: OpenDriver: trying /usr/lib32/xorg/modules/dri/tls/r600_dri.so
libGL: OpenDriver: trying /usr/lib32/xorg/modules/dri/r600_dri.so
libGL: dlopen /usr/lib32/xorg/modules/dri/r600_dri.so failed (/home/berocs/.local/share/Steam/ubuntu12_32/steam-runtime/i386/usr/lib/i386-linux-gnu/libstdc++.so.6: version `GLIBCXX_3.4.20' not found (required by /usr/lib32/xorg/modules/dri/r600_dri.so))
libGL error: unable to load driver: r600_dri.so
libGL error: driver pointer missing
libGL error: failed to load driver: r600
libGL: OpenDriver: trying /usr/lib32/xorg/modules/dri/tls/swrast_dri.so
libGL: OpenDriver: trying /usr/lib32/xorg/modules/dri/swrast_dri.so
libGL: dlopen /usr/lib32/xorg/modules/dri/swrast_dri.so failed (/home/berocs/.local/share/Steam/ubuntu12_32/steam-runtime/i386/usr/lib/i386-linux-gnu/libstdc++.so.6: version `GLIBCXX_3.4.20' not found (required by /usr/lib32/xorg/modules/dri/swrast_dri.so))
libGL error: unable to load driver: swrast_dri.so
libGL error: failed to load driver: swrast
^C

Solution:

mv /home/berocs/.local/share/Steam/ubuntu12_32/steam-runtime/i386/usr/lib/i386-linux-gnu/libstdc++.so.6 /home/berocs/.local/share/Steam/ubuntu12_32/steam-runtime/i386/usr/lib/i386-linux-gnu/libstdc++.so.6.bkup

sudo ln -s /usr/lib32/libstdc++.so.6 /home/berocs/.local/share/Steam/ubuntu12_32/steam-runtime/i386/usr/lib/i386-linux-gnu/libstdc++.so.6

sudo pacmatic -S ttf-liberation

ttf-liberation is to fix garbled text on the login screen.

intel video

(1/1) installing xf86-video-intel                                                               [########################################################] 100%
>>> This driver now uses DRI3 as the default Direct Rendering
    Infrastructure. You can try falling back to DRI2 if you run
    into trouble. To do so, save a file with the following 
    content as /etc/X11/xorg.conf.d/20-intel.conf :
      Section "Device"
        Identifier  "Intel Graphics"
        Driver      "intel"
        Option      "DRI" "2"             # DRI3 is now default 
        #Option      "AccelMethod"  "sna" # default
        #Option      "AccelMethod"  "uxa" # fallback
      EndSection

Coyote Raspberry Pi's

Wireless AP

Set up a network for SSH access or webserving.

Just network: wpa_supplicant, dnsmasq, hostapd.

Webservice: nodejs, authbind, rpi-monitor.

Set wlan0 to a static IP:

# /etc/dhcpcd.conf
# Append to file:
interface wlan0
static ip_address=192.168.0.1/24
static routers=192.168.0.1

Setup /etc/dnsmasq.conf:

# Append to end of /etc/dnsmasq.conf
# disables dnsmasq reading any other files like /etc/resolv.conf for nameservers
no-resolv
# Interface to bind to
interface=wlan0
# Specify starting_range,end_range,lease_time
dhcp-range=192.168.0.50,192.168.0.150,12h
# dns addresses to send to the clients
server=8.8.8.8
server=8.8.4.4
# Route all requests to this machine
address=/#/192.168.0.1

You may have to create /etc/hostapd/hostapd.conf:

# /etc/hostapd/hostapd.conf
ssid=YourWiFiName
wpa_passphrase=Somepassphrase
interface=wlan0
#bridge=br0
auth_algs=3
channel=7
driver=nl80211
hw_mode=g
#logger_stdout=-1
#logger_stdout_level=2
max_num_sta=5
rsn_pairwise=CCMP
wpa=2
wpa_key_mgmt=WPA-PSK
wpa_pairwise=TKIP

Serving site on port 80:

Configure authbind:

# touch /etc/authbind/byport/80
# chown user /etc/authbind/byport/80
# chmod 755 /etc/authbind/byport/80

To run a site:

$ authbind --deep node app.js

Links

http://elinux.org/RPI-Wireless-Hotspot

http://serverfault.com/questions/351108/using-dnsmasq-to-resolve-all-hosts-to-the-same-address

https://wiki.archlinux.org/index.php/Software_access_point

http://blog.sip2serve.com/post/48420162196/howto-setup-rtl8188cus-on-rpi-as-an-access-point

Backups

Noncritical

Non critical computers are those with unencrypted hard disks. These are things like 3d print servers or irc clients. If I take the time to encrypt a system, then I'll also encrypt the backups.

Backup Script in /opt/backup.sh

#!/bin/bash
# Backup either home or root
duplicity --no-encryption /home/berocs file:///mnt/bkup/${BNS-SYSTEM}/duplicity

Systemd Service /etc/systemd/system/backup-{root,home}.service

[Unit]
Description=Backs up /home/berocs to bns-readynas:/bkup/bns-daedalus/duplicity

[Service]
Type=Simple
ExecStart=/opt/backup.sh

Systemd Timer in /etc/systemd/sytem/backup-{root,home}.timer

[Unit]
Description=Timer for backup-{home,root}.service

[Timer]
OnCalendar=Monthly

[Install]
WantedBy=timers.target

cron line

RPi Notes

Failed to start Load Kernel Modules

On a Raspberry Pi.

Error:

$dmesg
[...]
Failed to start Load Kernel Modules.
[...]

Fix: edit /etc/modules-load.d/raspberrypi.conf and remove "bcm2708-rng" because it has changed to bcm2835-rng.

Debian Notes

On the servers I kept receiving the following error and bootup took almost 15 minutes.

Fri May  1 11:52:20 2015: Starting NFS common utilities: statd idmapd.
Fri May  1 11:56:33 2015: mount.nfs: Connection timed out
Fri May  1 12:00:46 2015: mount.nfs: Connection timed out
Fri May  1 12:04:58 2015: mount.nfs: Connection timed out
Fri May  1 12:09:11 2015: mount.nfs: Connection timed out

The problem ended up being nonexistant IP addresses in /etc/fstab due to the move from 10.10.x.x at Nick's house to 192.168.x.x at home. Fixing the fstab returns the servers to a fast boot.

Archives/Shop 3.0/Ctag computer notes

Contents

Overview

Naming Schemes

General Program Notes

SVG path to OpenSCAD

General Archlinux Notes

Systemctl Timed Out

GPG and Duplicity

bns-anarch

2013 Installation Notes

Thinkpad fan control

youtube-dl stacktrace

HP J4580 Unrecognized

Slic3r HTTPS API

ReText

MATLAB

Licensing

Manually

Automatically

Steam

Battle of Wesnoth

bns-kharselim

Installing Archlinux

Fixing the Thinklight

Resurfacing the keyboard

Firefox doesn't play nice with GTK Themes

Using a Brother DS-620

Libreoffice keeps segfaulting

qtcreator crash on help

r600 driver on steam

intel video

Coyote Raspberry Pi's

Wireless AP

Backups

Noncritical

RPi Notes

Failed to start Load Kernel Modules

Debian Notes

Navigation menu

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