Category: Tech

Debian Root on ZFS or just Home on ZFS

Helmut Neukirchen, 8. May 2024

As the Debian installer does not support to install on ZFS (due to potential legal incompatibilities between their licenses), this needs to be done manually (and as usual due to non-free firmware, Wifi is not supported out of the box by Debian, so you need to have an Ethernet cable connection):

I found a good Howto to have Debian Root on ZFS:

There are minor things to be noted:

  1. ashift=12 Some suggest that for SSDs a higher value might be better, e.g., 13. Still need to monitor wearout as ZFS has been reported to kill your SSD after a year.
  2. autotrim=on It is often said that rather a Cron jobs should do this, e.g., weekly.

Note that the above Howto contains also Rescuing using a live CD that might be helpful for rescuing.

I found two further howtos, that are somewhat different, due things in a slightly different order, but are more detailed and explicitly mention implicit steps:

I followed mainly the first howto with some inspiration from the two others. E.g. I created a standard swap partition. TODO: Enable swap and hibernate.

ZFS enables to do snapshots before and after system updates
(TODO: can this be added to any apt upgrade, incl. unattended upgrades?)

Note: After having selected KDE in tasksel, the system did not get KDE started: the textual boot was stuck at the latest task before KDE would be started (some cups stuff): I did then a apt install firmware-amd-graphics and after a reboot, it worked -- not sure whether a reboot alone would have already solved the problem or not.

For my T14, I also installed the WiFi drivers.

Home on ZFS

Somehow, the above installation was very unstable on my laptop (left mouse button not working after suspend, web browser often silently terminating), so I then used the normal Debian installer and just later moved /home to ZFS. Another argument in favour of not having root on ZFS is that in case of problems, having root on ZFS might be problem as ZFS is not natively supported by Debian (but in the above links, there is also a rescue approach mentioned). As an alternative, it has been suggested if snapshots for the root filesystem are a must, rather use BTRFS for that.

https://wiki.debian.org/ZFS for how to add ZFS.

https://theorangeone.net/posts/zfs-on-home/

https://www.shernet.com/linux/zfs-home-directory/

https://askubuntu.com/questions/1081238/migrating-home-to-zfs

EDIH-IS European Digital Innovation Hub Iceland opened

Helmut Neukirchen, 21. April 2023

The European Digital Innovation Hub Iceland (EDIH-IS) or in Icelandic: Miðstöð stafrænnar nýsköpunar has been formally opened. As name suggests, it serves as a hub to drive digital innovation, e.g. artificial intelligence, high-performance computing or cybersecurity, and connects industry and academia. University of Iceland is part of EDIH-IS and in particular the computer science department contributes in exactly these fields, i.e. artificial intelligence, high-performance computing or cybersecurity.

In fact, EDIH-IS has been operational already before that formal opening event and Auðna Tæknitorg, the Technology Transfer Office (TTO) Iceland is taking care of the day-to-day operations of EDIH-IS. For example, Auðna Tæknitorg/EDIH-IS is a partner in the Icelandic National Coordination Centre (NCC-IS) for Cybersecurity together with University of Iceland and other relevant partners.

Masters programme in Cybersecurity will get funded with 90 m.kr. by the Ministry of Higher Education, Science and Innovation

Helmut Neukirchen, 12. January 2023

The list of proposals that got funded. We are on place 4.

University of Iceland and Reykjavik University applied together for funding in order to start a joint study Masters's programme in Cybersecurity. Today, the Minister of Higher Education, Science and Innovation announced (including video recording) that the two universities will together get for the project Nytt meistaranám í netöryggi 90 million ISK funding over 2 years from the university collaboration fund (Samstarf háskóla). This is a great collaboration between the professors of computer science interested in cybersecurity at both universities (facilitated by EDIH-IS, the European Digital Innovation Hub in Iceland, where both universities are as well involved in digital innovation, such as Artificial Intelligence (AI) or High-Performance Computing (HPC)).

The new cybersecurity programme funding is announced (ignore the HA and Bifröst -- that's a typo)

While the schedule is tight, the plan is to offer as a start a Cybersecurity specialisation of the Computer Science Master's programme at each university already this autumn, i.e. 2023. Students can then apply at their preferred university, but take as well courses at the other university. (There is another project that got 35 m.kr. funding to enable technically, i.e. on the IT and learning management system side, but also administratively, i.e. collaboration contracts, taking master's courses at other universities. But I doubt that this is ready when we would need it already in autumn 2023.)

Update from autumn 2023: the Cybersecurity specialisation of the Computer Science Master's programme is available and you can enroll at University of Iceland or enroll at Rekjavik University.



Later, this Computer Science specialisation in Cybersecurity is supposed to become a study programme on its own.

The funding will be used to hire professors, but also to import distance teaching courses from abroad and to purchase equipment needed to set up a cybersecurity lab.

A presentation covers more details: Powerpoint / PDF.

Hvernig á að vera öruggur á netinu fyrir börn

Helmut Neukirchen, 16. November 2022
  • Farðu aðeins inn á netspjall með leyfi fullorðinna/foreldris!
  • Ekki spjalla við ókunnuga á netinu!
  • Ekki hitta fólk sem þú kynnist á netinu!
  • Ekki gefa upp persónulegar upplýsingar eins og nafn, heimilisfang, nafn skólans eða lykilorð!
  • Mundu að þú þarft ekki að tala við neinn á netinu ef þér líkar það ekki!
  • Spyrðu foreldra þína eða aðra fullorðna ef þú skilur ekki eitthvað á netinu!
  • Lokaðu strax öllu grunsamlegu á netinu og tilkynntu það til fullorðins sem þú treystir!
  • Ekki setja myndir á netið án leyfis foreldra þinna!
  • Internetið gleymir aldrei: það sem þú birtir þar getur verið sýnilegt þar að eilífu!
  • Ekki setja upp neitt á tölvuna þína án samþykkis foreldra!

Icelandic National Coordination Centre (NCC-IS) for Cybersecurity established

Helmut Neukirchen, 15. November 2022

We just established the Icelandic National Coordination Centre (NCC-IS) for Cybersecurity. It is is a common platform for cooperation in cybersecurity issues, composed of the following public entities: the Ministry of Higher Education, Science and Innovation, the Icelandic Centre for Research (Rannis), the Electronic Communications Office (ECOI/Fjarskiptastofa), the Computer Emergency Response Team (CERT-IS), the University of Iceland (UoI), Reykjavík University (RU), and the Technology Transfer Office (TTO/Auðna tæknitorg) Iceland.

NCC-IS operates in the context of Regulation (EU) 2021/887 of the European Parliament and of the Council of 20 May 2021 that establishes the European Cybersecurity Industrial, Technology and Research Competence Centre (ECCC) and the Network of National Coordination Centres (NCCs).

The core tasks of NCC-IS are:

  • Monitor and support actions: Monitoring and contributing to progress on national cybersecurity strategy activities regarding education, research, and development.
  • Provide expertise and link to ECCC and NCC-Network: Ensuring contribution to and coordination with the ECCC and the Network and supporting their strategic tasks.
  • Manage and coordinate funding: Managing and coordinating funding from the Digital Europe Programme and Horizon Europe for cybersecurity-related projects. Encouraging and assisting civil society, industry, SMEs, and academia in participating in cybersecurity actions (e.g., cascade funding, national funding contributions, etc.).
  • Raise awareness and build a cybersecurity Community: Acting as a central point for the national and European cybersecurity community, disseminating relevant outcomes of the work of the NCC-IS and NCC-Network, the Community, and the ECCC at the national level.
  • Develop and disseminate educational programmes: Coordinating, implementing and sharing educational activities and fostering cybersecurity skill building and training (e.g. gap analysis, competence mapping).
  • Support research and innovation: Identifying relevant research partners, promoting and strengthening dialogue in cybersecurity research and innovation fields.

Later, the NCC-IS will apply for European funding within the TOPIC ID: DIGITAL-ECCC-2022-CYBER-03-NAT-COORDINATION addressing the corresponding call for proposals call text.

To prevent any misunderstandings: NCC-IS will not take over the job of CERT-IS (or any other party) nor is NCC-IS a Security Operation Center (SOC). NCC-IS is rather an add-on to existing activities in order to raise awareness, co-ordinate actions, and improve education and research related to Cybersecurity on national and European level.

University of Iceland is in charge of developing and disseminate educational programmes, i.e. coordinating, implementing and sharing educational activities and fostering cybersecurity skill building and training. You are welcome to contact me if you are offering, e.g., training course or are interesting in getting updates on available training.

The NCC-IS at the Ministry of Higher Education, Science and Innovation.

Cybersecurity is now more in the focus of politics and has now an own government web page.

Crossover Office and Microsoft Powerpoint presentation user template storage location

Helmut Neukirchen, 5. January 2022

It took me some time to figure out where my PowerPoint 2007 stores the user specific presentation template. Assuming the bottle's C: drive is at ~/.cxoffice/Microsoft_Office_2007/drive_c/, then just copy your templates to
~/.cxoffice/Microsoft_Office_2007/drive_c/users/crossover/Application Data/Microsoft/Templates

Zoom Panopto integration

Helmut Neukirchen, 9. November 2021

Panopto can tell Zoom to copy Zoom meeting cloud recordings to Panopto. You can configure this automatic import/export by clicking in the very upper right corner of https://rec.hi.is/ on your user name and then select "User Settings".

University of Iceland is running Panopto with at least two different storage spaces: the old storage space used when logged-in to Panopto via UGLA (for Panopto videos accessible via UGLA) and the new storage space when logged-in to Panopto via Canvas (for Panopto videos accessible via Canvas).

On https://rec.hi.is/, you can in the upper right corner log out and log in to change between these two spaces. But you cannot copy videos between these two spaces -- but UTS help desk can do so.

For the Zoom integration, the problem is that recordings may end up in the wrong space: whatever the last log-in to Panopto was, sets the integration, i.e. tells Zoom where to store the video for all future Zoom session recordings. So take care that your last log-in was into the intended storage space before a Zoom cloud recording starts. (Or ask UTS help desk to fix it afterwards.)

Ice tea vs. IoT: LoRa

Helmut Neukirchen, 20. October 2021

Ice tea or IoT -- what do you prefer?

When I ordered the TTGO T-BEAM, I liked that it combines LoRa and GPS and it even supports a 18650 battery (18650 cells with internal protection circuit are somewhat longer, but still fit -- although very tight) including a good charging chip to charge the Li-Ion cell -- not LiFePO -- via USB (USB can also be used to power the device without using the battery holder). The ublox NEO-6M GPS chip has a dedicated backup (super)capacitor (looks like a coin cell battery) to buffer the GPS chips' RTC and almanach, but probably only for a few minutes.

Just when the delivery arrived, I found video #182 from Andreas Spiess, reporting that older TTGO designs had some design flaws: the 868-915 MHz versions have passive RF components (coils and capacitors to tune the frequency) that are not specific enough for the 868 MHz that we use here in Europe (some even fixed that) and the LoRa antenna could be better (all the videos by Andreas Spiess can only be recommended, including the LoRa videos). I was then happy to see that in newer designs, including the T-TBEAM, the WiFi antenna is placed better and in fact, the T-TBEAM even has a connector for an external WiFi antenna (but would need some minor soldering); also the LoRa and GPS part is now shielded by a metal cage. I was relieved to find the more recent video #224 measuring the T-BEAM and other newer boards, judging the newer designs to be OK.

I already expected that a better GPS antenna might be needed (and the tiny original one is only fixed with some adhesive tape that does not hold very well).

In summary, the T-BEAM seems not to be that bad (even the passive component that are too generic for 868 MHz turn out to be OK), but many reports indicate that the power consumption is rather high (that whole thread is anyway a worthwhile reading). 10 mA seem to be the minimum possible even during deep sleep. Concerning the power consumption, there seems to be an issue with deep-sleep. There is also a video on what is possible with ESP32 and deep sleep. Update: Meanwhile a student did as part of his M.Sc. thesis power measurements with the TTGO Lora32 (i.e not the T-BEAM) and the lack of going to deep sleep is confirmed there as well.

Some people complained that they got only 900 m instead of kilometers of range. The comments for video #224 mention that an older library had a flaw concerning the transmit power which did lead in that video to a low transmission power; according to the comments, this has at least been fixed now in the LoRa library by Sandeep Mistry that can be found in the Arduino Library Manager. Update: Again in our M.Sc. thesis, we achieved 15.5 km range.

A display can also be connected, but to reduce power consumption, it might be better to make it removable by using a female header.

Andreas Spiess recommends in his videos WeMos D1 ESP8266 and a Hope RFM95W LoRa module for which even a PCB is available (recommending as well WeMos D1 as ESP2866 board) -- it however needs SMD soldering. Nexus by Ideetron has elsewhere been mentioned as low power solution, but has only a small user base and thus lacks information -- and GPS can anyway be expected to be the big power consumer.
Concerning the LoRaWAN libraries, MCCI seems to be the only one that is actively maintained and communication with The Things Network needs to save some state information (for joining via OTAA) which MCCI stores in RAM that is not buffered in deep-sleep of ESPs. So for using OTAA, MCUs that do buffer the RAM (i.e. newer ATMEL MCU like in newer Arduino) would be preferable, e.g. Atmega 1284p together with a watchdog for waking up periodically has extremely low power consumption (0.5 μA in deep sleep) but lacks GPS. Other low power designs provide even triple GNSS and acceleration-detection watchdog. In addition to the ublox GNSS chips, there are some approaches that claim to reach lower power consumption by off-loading GNSS solver processing via LoRa to some external clouds server infrastructure or doing extreme A-GPS data compression for LoRa transmission from a cloud.

The really cool thing is that even satellites serve as LoRa repeaters (if there is a clear line of sight, LoRa has a theoretical range of 1300 kilometers, thus easily reaching low earth orbit satellites). By this, sensors that have no LoRa connection to a station on the Earth can still reach a LoRa repeater in the sky and forward their messages back to Earth. (But you need an amateur radio license for the used 70 cm frequency band: 435 MHz / 436 MHz up- and downlink.)

I also got two TTGO Lora32 v1.6.1 that have LoRa, a card reader, and a tiny display on the back, but not GPS. On one of them, the WiFi antenna was already loose when unpacking (see the 3D sheet metal in the photo below). Need to check how easy it is to solder it back again (or whether rather a hot air rework station is needed) or use it as opportunity to add an SMA/UFL connector? (There is also an UFL antenna connector, but since it as close to the LoRa SMA antenna connector, I guess the UFL connector is as well for LoRa -- after desoldering some 0 Ohm SMD resistor and creating a soldering bring/reusing that 0 Ohm SMD resistor.)
Even though TTGO Lora32 comes with a cable to connect a battery, TTGO Lora32 version v1.6 had a fire issue where the battery explodes. I checked the schematics: My v1.6.1 has this issue fixed and the TTGO T-BEAM uses anyway a different charging IC that is claimed to be pretty good.

Also, double check the pinout: some complain that the pinout provided by LilyGO can be wrong.

Depending on the applications, I might use LoRa for device-to-device commnication, or LoRaWAN via The ThingsNetwork that has a coverage in Reykjavík, but fair use limits, e.g. 10 messages to the device per day, which could be avoided by setting-up my private LoRaWAN using ChirpStack.

Talking about lora (a popular name for parrots as the Spanish word for parrot is loro): did I mentioned already that the Computer Science department has moved and already a new visitor...?

DIY DVB-T/DVB-T2 indoor sleeve antenna made out of a coax antenna cable

Helmut Neukirchen, 13. October 2021

As the DVB-T sender has been moved here within Reykjavík, I had to adjust my indoor antenna which is simply built by turning a coax-antenna cable into a half-wave dipole antenna (essentially, a variant of a sleeve antenna) : the outer insulation of the coax cable was removed so that the part with the inner wire has a lambda/4 length and the left-over shield was peeled and turned inside out over the insulation so that it also has lambda/4 length (in sum: lambda/2). The aluminum foil that was part of the shielding was removed and finally, the inner insulation removed so that the inner wire remains totally uncovered. Take care that remainders of the shield do not touch the inner wire.

For the details, including the calculations, see: http://www.vdr-wiki.de/wiki/index.php/DVB-T_Antennen (in German, but the calculations work in any language -- note that they use a correction factor of 0.95 for the length of the shield and 0.97 * lambda/4 for the length of the inner wire -- but, well, the antenna needs to cover some frequency range, so these corrections probably matter not that much).

More info on the senders in Iceland can be found at https://vodafone.is/sjonvarp/sjonvarpsthjonusta/thjonustusvaedi/ (see map at the bottom). The sender operated by Vodafone on Úlfarsfell broadcasts on three UHF channels with 8 MHz bandwidth:

  • Channel 26 (514 MHz center frequency): RÚV HD (DVB-T2), RÚV 2 HD, BBC Brit, DR1, Food Network, Hringbraut, N4, National Geographic, Rás 1, Rás 2, Rondo (the latter are not TV, but radio)
  • Channel 27 (522 MHz center frequency): RÚV (DVB-T only), Stöð 2, Stöð 2 Bíó, Stöð 2 Fjölskylda, Stöð 2 Sport, Stöð 2 Sport 2, Rás 1, Rás 2, Bylgjan, Fm957 , Léttbylgjan, Xið
  • Channel 28 (530 MHz center frequency): Stöð 2 Golf, Stöð 2 Sport 3, Stöð 2 Sport 4, Animal Planet, Discovery.

Using 522 MHz, lambda/4 is 14.36 cm which I used for the above DIY antenna.

With the older sender where I had an unblocked line of sight, the reception was yielding almost 100% signal strength and signal quality, but with the new location of the sender on Mt. Úlfarsfell, my reception got really bad (there is a hill and high buildings in the line of sight) and signal strength is even fluctuating, which might be explained by the weather, e.g. rain can be expected to weaken the signal strength.

In addition to the above programmes, my TV receives a far stronger DVB-T signal on on channel 41 (634 MHz -- which means the calculated lambda/4 does not fit perfectly, still the received signal strength is close to 100%) which must be another sender than the one from Vodafone (it anyway broadcasts missionary programmes only).

Eclipse, modular projects and JUnit

Helmut Neukirchen, 21. September 2021

I (and many others) always had problems making JUnit (as added by Eclipse automatically when creating JUnit test cases) work with modular projects, i.e. projects that use module-info.java files to define dependencies. Finally, I found solutions:

  • Let the new project wizard not create the module-info.java file -- deleting it afterwards might not be enough as Eclipse did already some modification the the module path settings (OK, trivial) or
  • Choose Java ≤8 in settings (i.e. module-info.java ignored -- again: trivial) or
  • Apply quick-fixes: in the class containing your JUnit test cases, hover over the org.junit.jupiter.api import and select the quick-fix: “Add ‘requires […]’ to module-info.java”. Then in module-info.java: hover with mouse over the squiggle line (the important point is: clicking on the light bulb does not give any quick-fix, so you need to hover) and do: “Move classpath entry ‘JUnit5’ to modulepath”. This should fix it! or
  • Create an Eclipse project with extra src folder (e.g. src-test or use the Maven default structure) that has (via “Allow output folders for source folders”) its own output folder (e.g. bin-test or use the Maven default structure) and that has “Contains test sources” toggled to “Yes” (in project properties - Java Build Path -Source). The test src folder should then have a more grey-ish icon. Either do this with the New project wizard, or afterwards using project properties. As a result, JUnit is then not part of the modular project anymore. (Has also the advantage that test code is better separated.)