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Jeroen W. Pluimers on .NET, C#, Delphi, databases, and personal interests

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Archive for the ‘Linux’ Category

listing files with ISO 8601 time stamps on *n*x flavours

Posted by jpluimers on 2018/12/05

A (long!) while ago, I wrote about list date with seconds from ls command – Dev Shed that showed how to list the full ISO timestamp (including seconds) of files.

This is an update.

The previous post showed that you could use this statement to list all files with their full ISO timestamps (and therefore get both the seconds and milliseconds) on (open)SuSE Linux, Mac OS X and Cygwin:

ls -l --time-style=full-iso

What Linux and displaying dates in ISO 8601 format… : Little Green Delusions proposes are two solutions to make this more permanent:

alias ls='ls -l --time-style=long-iso'

or edit one of your profile files (he prefers /etc/profile.local, but that is system wide, so I usually prefer ~/.bash_profile) to add this line:

export TIME_STYLE=long-iso

The thing is: I do not always want to have ls -l show ISO 8601 dates. I like the way that ls-l lists timestamps for very old or future files:                 Read the rest of this entry »

Posted in *nix, Linux, openSuSE, Power User, SuSE Linux | Leave a Comment »

how can I free up space on /boot as “openSUSE-2014-462” fails to install on openSUSE 12.3 x86_64

Posted by jpluimers on 2018/11/30

From a long time ago:

[WayBackhow can I free up space on /boot as “openSUSE-2014-462” fails to install on openSUSE 12.3 (x86_64):

Installation of kernel-desktop-3.7.10-1.40.1 failed:
(with --nodeps --force) Error: Subprocess failed. Error: RPM failed:     installing package kernel-desktop-3.7.10-1.40.1.x86_64 needs 16MB on the /boot filesystem

Based on that thread, I figured out the steps:

Read the rest of this entry »

Posted in *nix, Linux, openSuSE, Power User, SuSE Linux | Leave a Comment »

SSH: Connection Reset by Peer – Server Fault

Posted by jpluimers on 2018/11/22

One occasion I had SSH throw a Connection Reset by Peer on my when was the SD-card of a Raspberry Pi started failing and the ext4 filesystem got mounted in read-only mode.

Then sshd was still listening on port 22, but since it could not write to disk any more, it threw a Connection Reset by Peer to the client.

It was on OpenSuSE Tumbleweed, but would failed just as well using Raspbian.

Lessons learned:

  • IoT hardware will fail.
  • ext4 breaks when the hardware breaks.

–jeroen

Reference:

Posted in *nix, *nix-tools, Debian, Development, Hardware Development, IoT Internet of Things, Linux, Network-and-equipment, openSuSE, Power User, Raspberry Pi, Raspbian, SuSE Linux, Tumbleweed | Leave a Comment »

Install on openSUSE / SLES – Zabbix.org

Posted by jpluimers on 2018/10/29

Interesting: [Archive.isInstall on openSUSE / SLES – Zabbix.org is possible and there are packages for this on the OpenSuSE site itself for the various kinds of distributions.

For instance, Tumbleweed is at http://download.opensuse.org/repositories/server:/monitoring/openSUSE_Tumbleweed/

Good introductions on Zabbix are via [WayBackStephen Fritz on Systems Engineering: Installing and Configuring Basic Zabbix Functionality on Debian Wheezy who has a [Archive.is] zabbix tag.

Other links are at Welcome to workaround.org – tips around open source and Linux stuff.

And there is www.zabbix.com/documentation

–jeroen

Posted in *nix, Linux, openSuSE, Power User, SuSE Linux, Tumbleweed | Leave a Comment »

MotionEyeOS on Odroid C1+ with Logitech USB web cameras

Posted by jpluimers on 2018/10/11

Hopefully I get this to work after fixing

The first part of the fix was to

  1. re-image the SD card.
  2. boot
  3. wait 5 minutes (there is no output on HDMI apart from some flickering and no output on TTY using 115200 bits/second despite trying [WayBacken:c1_hardware_uart [ODROID Wiki])

The second part is getting the USB web cameras to work.

I’ve got two types, but the label on them doesn’t list their common name, only their P/N sometimes with M/N:

  1. P/N 860-000049 M/N V-UBC40 (really old USB cameras)
  2. P/N 860-000334 (new USB camera)

The MotionEyeOS web interface didn’t list any working cameras so I had to do some digging.

Luckily [WayBackWebcam software and driver support for Windows has a table of part and model numbers combined with product names, so they got revealed them as these:

  1. P/N 860-000334 = M/N V-U0028  with name HD Pro Webcam C920
  2. P/N 861225 = M/N V-UBC40 with name Quick Cam Messenger
    (which is funny as the P/N on the label is different)

Both are supported by motion according to [WayBackLogitech < Motion < Foswiki though the Quick Cam Messenger needs [WayBackQuickcam Messenger & Communicate driver for Linux which I should try to cross-compile one day.

The latter works fine. Below are some settings I used.

Read the rest of this entry »

Posted in *nix, Development, Hardware Development, Linux, Odroid, Power User | Leave a Comment »

Notes on recording audio calls from a Fritz!Box and playing back those captures calls

Posted by jpluimers on 2018/09/28

A while ago, I documented some links for In case I ever need to record calls on my Fritz!Box devices.

By now, I’ve done a bit more investigation: I’ve enabled the call monitor, did some port scans, installed domoticz and got deeper into fritzcap.

Oh and I got packet capturing to work too: Fritz!Box – capture network packets in Wireshark format or ISDN in dtrace format.

A small recap so I don’t forget what I did and what the effects were.

Enabling CallMonitor

[WayBackFritzbox – Domoticz showed how to enable the CallMonitor option in your Fritz!Box

  • Dial #96*5* to enable (response “CallMonitor On”)
  • Dial #96*4* to disable (response “CallMonitor Off”)
  • It seems not possible to ask for the current state (enabled/disabled)
  • After it is enabled, the TCP port 1012 on your Fritz!Box is available for tools like [WayBackDomoticz and fritzcap.

Read the rest of this entry »

Posted in *nix, Fritz!, Fritz!Box, Internet, Linux, openSuSE, Power User, SuSE Linux | Leave a Comment »

Not cool: openSuse Tumbleweed switched DHCP clientID algorithm on Raspberry Pi 3, so now all devices get a non-static DHCP address

Posted by jpluimers on 2018/09/15

Not sure in which changeset this happened, but here is one example:

  1. old DHCP client ID 1:b8:27:eb:1a:b1:ec
  2. new DHCP client ID ff:eb:78:a9:4:0:1:0:1:22:6:67:49:b8:27:eb:78:a9:4

The first one was marked static in the DHCP server, which means the Raspberry Pi now did get a different IP address.

This messes up a few places that cannot do proper address resolution.

Anyone who knows where this has changed / is configured?

These did not help finding the cause:

Edit

As commented by Leen below, this is about

Wicked changed its defaults to use this DHCPv6 compatible RFC4361 client-id in favour of the older RFC2132 client-id. However, this has caused some issues with older DHCPv4 servers and existing setups where the client-id stored by the server is used to assign a (static) address. It is recommended to fix this server-side, but still, wicked provides several ways of addressing this issue

So here are some links:

–jeroen

Posted in *nix, Hardware Development, Linux, openSuSE, Power User, Raspberry Pi, SuSE Linux, Tumbleweed | 6 Comments »

Some Linux mail solutions

Posted by jpluimers on 2018/09/07

Too bad most of them are very picky to the Linux distributions they run on.

–jeroen

Posted in *nix, Linux, openSuSE, Power User, SuSE Linux | Leave a Comment »

Linux: See Bandwidth Usage Per Process With Nethogs Tool – nixCraft

Posted by jpluimers on 2018/08/24

This tutorial explains how to find out network bandwidth usage per process in real time using nethogs tool under Linux operating systems.

Cool tool!

Source: [WayBackLinux: See Bandwidth Usage Per Process With Nethogs Tool – nixCraft

An alternative is iftop – Wikipedia.

via:

–jeroen

Posted in *nix, *nix-tools, Linux, openSuSE, Power User, RedHat, SuSE Linux, Tumbleweed | Leave a Comment »

when bind named service hasn’t started after OpenSuSE Tumbleweed boots

Posted by jpluimers on 2018/08/20

A while ago, named would not start any more after I rebooted my Tumbleweed systems.

I had this behaviour on multiple systems, each installed quite a while ago and kept up-to-date with zypper dist-upgrade so it looked like a systematic issue.

Below are steps in researching the problem together with the helpful people on the IRC channel opensuse-factory.

Background reading for some of the commands: [WayBackHow To Use Systemctl to Manage Systemd Services and Units | DigitalOcean.

Both systemctl status named.service and systemctl status named would show the same output:

# systemctl status named
● named.service - LSB: Domain Name System (DNS) server, named
   Loaded: loaded (/etc/init.d/named; generated; vendor preset: disabled)
   Active: inactive (dead)
     Docs: man:systemd-sysv-generator(8)

Getting the log from events around a reboot would show a successful shutdown, but no start:

# journalctl --unit named --catalog --pager-end

Apr 28 13:19:27 laurel systemd[1]: Stopping LSB: Domain Name System (DNS) server, named...
-- Subject: Unit named.service has begun shutting down
-- Defined-By: systemd
-- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel
-- 
-- Unit named.service has begun shutting down.
Apr 28 13:19:28 laurel named[20360]: no longer listening on 192.168.124.27#53
Apr 28 13:19:28 laurel named[20360]: no longer listening on 192.168.124.27#53
Apr 28 13:19:32 laurel named[20360]: received control channel command 'stop'
Apr 28 13:19:32 laurel named[20360]: shutting down: flushing changes
Apr 28 13:19:32 laurel named[20360]: stopping command channel on 127.0.0.1#953
Apr 28 13:19:32 laurel named[20360]: no longer listening on ::#53
Apr 28 13:19:32 laurel named[20360]: no longer listening on ::#53
Apr 28 13:19:32 laurel named[20360]: no longer listening on 127.0.0.1#53
Apr 28 13:19:32 laurel named[20360]: no longer listening on 127.0.0.1#53
Apr 28 13:19:32 laurel named[20360]: exiting
Apr 28 13:19:34 laurel named[30705]: Shutting down name server BIND  waiting for named to shut down ..done
Apr 28 13:19:34 laurel systemd[1]: Stopped LSB: Domain Name System (DNS) server, named.
-- Subject: Unit named.service has finished shutting down
-- Defined-By: systemd
-- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel
-- 
-- Unit named.service has finished shutting down.

Similar results in these files:

  • /var/lib/named/log/general.log

28-Apr-2017 13:19:32.465 general: shutting down: flushing changes
28-Apr-2017 13:19:32.468 general: stopping command channel on 127.0.0.1#953
28-Apr-2017 13:19:32.622 general: exiting

  • /var/lib/named/log/named.log

28-Apr-2017 13:19:32.489 network: no longer listening on ::#53
28-Apr-2017 13:19:32.489 network: no longer listening on 127.0.0.1#53

With systemctl, I got this:

# systemctl is-enabled named
named.service is not a native service, redirecting to systemd-sysv-install.
Executing: /usr/lib/systemd/systemd-sysv-install is-enabled named
enabled
# systemctl is-active named
inactive
# systemctl is-failed named
inactive

After this, I was out of systemd and sysv knowledge, so I asked for help on the #openSUSE-factory IRC channel, where ismail was of great help.

Read the rest of this entry »

Posted in *nix, *nix-tools, bind-named, Linux, openSuSE, Power User, SuSE Linux, Tumbleweed | Leave a Comment »