Índice para February 2022 em Linux Format

Jonni Bidwell Paranoid? Moi? Well, apart from using the sandwalk to cross town (because who knows when the Shai-Hulud will strike?) I sometimes like to prefix my bash commands with a space so they’re not committed to the history file. I also like to torch my work machine at the end of every day. Tim Armstrong There are many things that I do that others might consider paranoid. Something I recommend using virtual credit cards and ephemeral email addresses when shopping online. This helps to prevent targeted ads, spam, fraud, identity theft and purchase history harvesting. Les Pounder Each OS release, be it Ubuntu on my desktop or Raspberry Pi OS. I always back up and perform a fresh install. To me it makes sense because I get a fresh…

When did you last test your smoke alarm? And what’s that got to do with Linux anyway? Last week our smoke alarm went off at home. My wife had forgotten that she had something on the hob that was now smoking. She was alone, and she’s deaf so she didn’t hear the smoke alarm. Fortunately we have a Rhys, who is a hearing dog. He found her and gave her the signal that the smoke alarm was going off. Shocked, my wife sorted out the situation in the kitchen before there was a fire. Thank you, Rhys. So here’s how it works. Rhys is trained to notify my wife when he hears certain sounds. He notified her when he heard one, and corrective action was taken. All pretty straightforward. You…

I write this as 2021 comes to a close and we look to the year ahead. The past year has been eventful, both for society as a whole, as well as in the Linux community. We started the year just after the release of Linux 5.10, an LTS (Long Term Support) kernel for which updates will be available for years to come, and we end the year with the imminent release of 5.16. Over the past year many new features have been merged into Linux, benefiting a range of systems. Embedded Linux gained support for the ACRN hypervisor targeting functional safety environments, as well as most of the rest of the guts of the “preempt-rt” Linux Real Time patches. On the phone front, Linux gained a new “process_ madvise” system…

Q Sharing photos I’ve been copying my photos from my phone onto my laptop now for a while. Up until now I’ve been using Shotwell to automatically download and move my photos into the photo store. However, I think I need to start thinking about moving these photos onto a server. I’d like to make it easy for us to be able to upload photos directly to the server (maybe even directly from the phone) and be able to potentially view them from the phone too. However, I don’t think it’s as simple as lifting and shifting those photos onto some form of NAS because Shotwell has a database with tags, and I’d like to preserve the few tags that I have. I suppose I’d also need a server of…

Welcome to our Roundup of the best backup tools currently available for Linux. For this month’s article, we’ve concentrated on GUI tools aimed at the general user, else you should be using rsync. These tools range from the most basic and easy to set up, to those that offer more complex options and facilities, and we’ve stuck to tools that are currently maintained. We’re interested in backup programs that can carry out user file backups – usually the contents of the /home directory. These tend to be the most important files for a backup system, because they can’t easily be replaced if lost. In effect, the installation media for your operating system is your backup of the system files themselves. All of the programs that we’re looking at are front…

Most people benefit from a scheduling routine when it comes to backups. Ideally, it’s useful to be able to specify the time of backup in order to avoid busy periods. In addition to the built-in scheduling, all of these programs can be controlled via a cron job, if you know how to set that up on your system. However, we can’t give the same marks for a program that relies on doing this as opposed to built-in scheduling. Grsync doesn’t support scheduling via the user interface, but a specific profile can be run using a cron job. Like most of the program’s functionality, Deja Dup certainly keeps things simple when it comes to scheduling. You can specify ‘Back Up Automatically’ in the preferences and then select either daily or weekly…

We’re not sure about this cryptocurrency malarkey. And we’re even less sure about people co-opting the term ‘crypto’ which for years has been used by cypherpunks as an abbreviation for the nobel art of cryptography. But one thing we can thank cryptocurrency for is ransomware. If victims were instead asked to pay regular, ‘fiat’ money to a bank account, or money transfer, they’d be much less likely to pay. And, thanks to banks in most countries being pretty wise about knowing their customers, the scammers would be much more likely to be caught. But over the past decade and a bit ‘crypto’ (in particular Bitcoin) has cemented its position as the premiere conduit by which to receive ransomware payments. It’s often said that Bitcoin payments are hard to trace. But…

Recently Nextcloud has been making the headlines for speaking out against Microsoft’s monopolistic practices. Indeed, it seems that history has gone full circle, but instead of getting into antitrust trouble for bundling its browser with Windows (like it’s 1999) this time Frank Karlitschek wants the European Commission (and in a separate complaint German authorities) to examine the inclusion of OneDrive and Teams with the OS. Our boy Frank may have inadvertently poised himself as the Netscape character in our analogy here, but we think he’s right. We might have softened our collective editorial stance on Microsoft over the years, but this sort of behaviour is harmful. There’s not much point launching a competing service to Onedrive when users find Onedrive not only pre-installed, but deeply integrated into the operating system.…

The Raspberry Pi isn’t exactly short of display options. We have HDMI, DSI and SPI screens via the GPIO. The latter option (SPI) is where we see the Display HAT Mini, which connects to all of the GPIO pins, but only uses 13. We can access the free GPIO pins using a breakout board, such as Flat Hat Hacker. The Display HAT Mini features a two-inch (320x240px) IPS screen. While small, the screen is clear and easy to read, thanks to IPS technology which permits greater viewing angles and bright vivid images. Display HAT Mini’s form factor lends itself to the Raspberry Pi Zero range of boards, too. Display HAT Mini excels as a simple user interface and information output for embedded projects. Think home automation, network and server data.…

Booting an operating system on the Raspberry Pi is straightforward, but the tools used for the process have changed over the years. Since the release of the Raspberry Pi 4 and the Pi’s slightly different architecture, new utilities have been developed, both for single installations and for multibooting. Meanwhile, the price of SD cards has plummeted. While the basic tools – Raspberry Pi Imager, Etcher and so on – are suitable for single booting, BerryBoot is particularly useful for multibooting, as is NOOBS. There is also a web-based solution that automates single and multiboot installations via your browser, called PINN. Everything explained here assumes you’re using a Raspberry Pi with a keyboard, mouse and monitor attached, with an accessible network connection. The Raspberry Pi has a decent selection of operating…

Interested in multibooting your Raspberry Pi? Choosing the right combination of operating systems will save considerable messing around later on. But what’s the best mix? While it depends on which multiboot system you’re using, here are some suggestions that can be put together using PINN, the web-based multiboot configuration tool. For a system that balances gaming and media, you can install Recalbox and Lineage, delivering the full entertainment centre experience. A more lightweight alternative is RetroPie and OSMC, which have smaller disk space requirements. Have desktop requirements? Two paths here are to add a full Raspberry Pi OS, Ubuntu 20.10, Gentoo, or Manjaro to any of the above. You might even install all four. Small hard disk drive, or just need an OS that does the basics? PINN has Arch,…

The Guix developers and maintainers have made a clear choice to only support hardware that accepts open source drivers. In your common distributions, there are some closed source blobs. Your kernel in Guix is the Libre kernel, which has only open source drivers. On many systems, you can run this without a problem. Some systems though, need proprietary drivers to run all hardware and even boot. When you consider Guix, you need to check if your hardware is in its list that protects your freedom. To make sure, head to the Free Software Foundation web page (www.h-node.org/search/form/en). You can search for your hardware in its database, but the simplest approach is to print your lspci -vmmnn . You can dump the printout into its form and it outputs a full…

The Diskgraph utility (https://github.com/stolk/diskgraph) can be used to chart the IO data in real time. Written in C, the project has no dependencies to speak of, and if you already have gcc installed on your distribution you can install Diskgraph without any issues. Download the repository with the git clone https://github.com/stolk/diskgraph.git command. Next, change into the downloaded diskgraph repository. You’ll find a number of files, including Makefile. So, run the make command. That’s it! You’ll now notice a new executable diskgraph script. The diskgraph utility requires a device to monitor, so run the ./diskgraph sda command to monitor the sda hard disk. You don’t have to specify disks using the complete path such as /dev/sda although that is also supported. The Diskgraph utility works by studying how many sectors are…

“On Windows!!” We hear you scream. We know that Windows isn’t really the focus of Linux Format, but hear us out. For those of you not yet ready to make the leap to Linux (perhaps Windows 11 will force your hand) and who want to emulate Commodore machines then there is a ready-to-go alternative. www.c64forever.com from Cloanto is an all-in-one package that can emulate the VIC-20 along with various models of Commodore PET, Commodore 16, Plus/4 and the Commodore 128. This package provides all the configurations and ROMs, legally. C64Forever employs a clear user interface that enables you to choose your system and it even provides a selection of popular games and demoscene demos. There’s also AmigaForever, which as you can guess emulates many different Amiga machines. If C64Forever and…

Audacity might provide a suitable tool for post-processing recordings, but you wouldn’t choose to use it on stage. For a start some effects involve lots of number crunching so they won’t work in real time, and second you might not want to have a laptop at your feet on stage. In the early days, effects were produced using small pedals containing analogue electronics and, while analogue pedals are still available today and are preferred by some performers, many pedals now contain a digital alternative. Having got to grips with the physics of effects using GNU Radio Companion, if you’re a performer you might feel inspired to make your own pedals and there’s never been a better time. Indeed, single board computers such as Raspberry Pis and Arduinos offer suitable platforms,…

We’ve already mentioned some of the tools to manage and restrict bandwidth, and most people will use the GUI to create and manage virtual machines. Sometimes there’s a need to be able to do it from the command line, for example inclusion in a script. The VirtualBox management tool, as previously noted is VboxManage. To list all the VMs, just use VboxManage list . There’s also an additional set of switches that can be used to provide more insight, such as restricting the output to only running VMs. (VboxManage list runningvms) Alongside this, there are power options to power off and power on the VirtualBox VMs (VboxManage startvm with the appropriate VM identified or even powered off using the same command format). Pretty much anything that can be done via…

There are millions of people on the Fediverse, and as a rule, they tend to be a lot more interesting than who you’d find on Facebook or Twitter. Because servers tend to be organised around themes, once you find one person you like to follow it’s fairly easy to find more thanks to the federated timeline. Here are a few of our favourite servers and individuals: Free software and related matters: Fosstodon.org Hard-core Linux and programming: nixnet.social Writer and Linux historian: https://mastodon.social/@glynmoody M’aiq the Liar – a wisdom-filled cat-person from Skyrim. https://fandom.ink/@lyingkhajiit The latest news from the UK’s greatest popular science mag: https://mstdn.social/@newscientist Wired magazine – the second best tech publication on Earth: https://mstdn.social/@Wired The official account of the desktop environment adored by millions: https://floss.social/@gnom These are good starting points,…

Calm down vicar. The gin we’re talking about is an open source web framework (a collection of libraries and APIs) written in Go that can help you develop powerful HTTP services. All the code discussed here can be found in the https://github.com/mactsouk/LXF.285 GitHub repository. If you want to download all the code for this tutorial from GitHub then you’ll need to run the following three commands: You need to run cd LXF.285 to go into that directory. We’re now ready to continue with the rest of the tutorial. A basic server One of the files found in the repository is called introGin. go and is located inside the /simple directory. introGin. go implements a simple HTTP server and is going to be used in this section to help you understand…

We can’t talk JSON without talking marshalling and unmarshalling of JSON records stored in Go structures. When working with JSON data over network connections, marshalling and unmarshalling are compulsory processes required to successfully exchange JSON data. Marshalling is the process of converting a Go structure into a JSON record. Unmarshalling is the process of converting a JSON record provided as a byte slice into a Go structure. You usually want that when receiving JSON data via computer networks or when loading JSON data from disk files. json.Marshal() is used for marshalling and json.Unmarshal() is used for unmarshalling. This happens because you can’t transfer JSON data over computer networks as Go structures. The good thing is that, if you want, Gin can perform all JSON operations for you. This means you…

If you weren’t taking your security seriously before, it’s time to start. I’m not about to start saying silly things like “it’s the year of malware on Linux”. Unix-based systems have always had malware, but in many ways the targets are reversed to those of Windows. Linux has a tiny consumer base but a huge business, server and IoT base, and so commercial ransomware or hacking attacks and IoT botnet capture are favourite methods employed by criminals. Contrast this with Windows and its huge consumer base (running out-of-date builds) as a target. But the world is changing, if slowly. It takes a long time to overhaul a market that’s almost entirely geared to offering Windows-based products, you know. However, the arrival of Steam Deck in early 2022 alongside the continuing…

Last issue we reported on how popular YouTube channel Linus Tech Tips published a video showing the team struggling to use Linux for various basic tasks. This led to a backlash against the team behind the distro used (Pop!_OS), while many others worried that the video damaged Linux’s reputation by seemingly confirming many people’s fears that the operating system is buggy and overly complicated. Since then there’s been a far more positive development, with many members of the Linux community coming together to list all of the issues that the Linus Tech Tips team encountered, and working on fixes. You can see the list of issues at https://bit.ly/lxf285github. It’s also inspired 10-year-old Rudra Saraswat to create a new distro, Gamebuntu, that could help newcomers to Linux who want to play…

Linus Torvalds announced Linux 5.16-rc5, noting that it had been “a bit bigger than usual” but attributing this to “people trying to get stuff done before the holidays”. The forthcoming kernel will add support for Intel’s “AMX” (Advanced Matrix Extensions), RISC-V virtual machines, and a wealth of new graphics including the integrated graphics on Intel Alder Lake platforms. Deep in the new kernel, the default amount of memory that applications can “lock” into place (prevent being swapped) has been upped to 8MB but this has led to debate about the relative tradeoffs involved. The 8MB limit (RLIMIT_MEMLOCK) affects the Linux “mlock” system call, which is typically used by GnuPG and similar privacy sensitive software that doesn’t want your confidential encryption keys – loaded into memory to encrypt or decrypt sensitive…

Sometimes you may execute a shell command and find that its behaviour doesn’t match that of the man page. This is because most shells, like Bash and ZShell, have duplicates of a number of core commands built in. This is done for speed and efficiency: the command doesn’t have to be loaded from disk before it can be used – it’s already loaded as part of the shell. You can find a list of built-in commands in the man page for your shell (the bash man page is long, but the information is in there). You can tell if a command is a built-in one or not with the type command: So what do you do if you want to run the “standard” version of the command rather than the…

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Intel has made much of its work with Microsoft to enable smooth utilisation of its P and E cores, and recommends people use Windows 11, but what about the Linux? Intel so far has provided no patches to the kernel for the required Intel Thread Detector optimisations, and it missed the 5.16 window, so in all likelihood it’ll be another four months before any patches – presuming they materialise as Intel does have a good kernel contributor track record – make it into a mainline distro that’s not an Arch-based one. The result is that some workload threads end up on E cores when they should be on P, so although everything works fine there are occasional performance hiccups; it most affects high-end games. The situation has been alleviated by…

We wanted to get an idea of what each package would be like to install, configure and use, and to this end, we installed each package on a fresh system. We chose Ubuntu 21.10 as our testbed system, but we checked to make sure there was nothing stopping the backup software from being installed on other popular systems. We then set each piece of software up and configured it, making notes of any difficulties or inconveniences that cropped up along the way. For each program, we set up an actual backup using real user data. We then evaluated both the back up process itself and the user experience that it took to get to that point. We tested it with real user data because, quite frankly, any piece of software…

Bacula (www.bacula.org) is a stalwart of the Linux backup scene and one that has reduced grown system administrators to tears. It could have been included in our main list because it has an optional GUI front end, but it’s not aimed at typical users backing up their own files. We’ve looked at user file backup systems, so we didn’t consider a tool like Clonezilla (https://clonezilla.org/), which makes copies of entire disks including the system files. Pure snapshot style utilities are also useful for a different type of backup. The Btrfs only TimeShift is an example of this and it can back up an entire system extremely quickly. Then, if you make a change to your system, you can quickly revert it to a previous state. For some, it might be…

It’s worth remembering that a determined and resourceful adversary could probably hack a regular desktop Linux user if they wanted to. But that doesn’t mean we should give up, switch off our firewalls and scream, “It’s PASSWORD1” into the bleak night. Recycled passwords are a common cause of attack and there’s no reason not to be using a password manager today. We recommend the open source KeePassXC (https://keepassxc.org) but there are all kinds of other FOSS offerings, as well as cloud solutions. If you prefer things text-based, there’s the pass program that can manage a clean password heirarchy via GPG and (optionally) Git. Protecting your important accounts with Two Factor Authentication (2FA) should be a given now. And using your phone as a second factor isn’t infallible. Many applications and…

As we approach 10 years of Raspberry Pi, I’ve had a think about all that’s happened during this time. The first Pi went on sale on 29 February 2012, and sites selling the device crashed a few moments after release. It’s grown from a curiosity into a serious low-power desktop computer. The children who cut their teeth on the Pi in the past decade are the adults enacting change with the Pi. Science experiments, drones, robots, games consoles and more have been created with it. So who’s to thank for all of this? Part of the credit must go to the Raspberry Pi Foundation of course, for sparking the minds of learners young and old. But the largest thanks go to you – the community. Before Covid we met at…

While reviewing the Pimoroni Display HAT Mini (see page 43) we created a quick project to demonstrate how easy this screen is to work with, and how useful the QW/ST connector is. The project uses an AHT20 temperature sensor to collect data, which is then displayed on Display HAT Mini’s screen to create a mini temperature monitor station. With the Raspberry Pi powered off, connect the Display HAT Mini to the GPIO and use the included standoffs to secure the screen to the Pi. Take care pushing it onto the GPIO – the screen is fragile. Now is also the time to connect the AHT20 sensor to the QW/ST connector on the HAT. Connect your keyboard, mouse etc and then power up your Pi to the desktop. From the main…

Using a microSD card to boot the Raspberry Pi isn’t the only option you have. The Raspberry Pi 4 and 400 both support booting from USB rather than a microSD card. This opens up a range of options. USB flash sticks, USB hard disk drives, solid-state drives with USB, even NVMe devices with a USB adapter can be hooked up to the Pi 4 to boot up. Most of these devices are likely faster than a standard microSD card, and certainly more resilient. Consequently, the option is now available to prioritise disk speed and performance by choosing to move away from the traditional microSD booting method. Enabling booting for the Raspberry Pi 4 and 400 is straightforward, but can only be done easily using Raspberry Pi Imager. When selecting the…

1 Select an SD card size Multibooting your Raspberry Pi doesn’t have to rely on BerryBoot or any other downloadable tool. With PINN, you can manage it all in your browser. You’ll find the PINN tool at https://pinn.mjh.nz, where you’re immediately prompted to select your storage device and capacity. You can choose an SD card, USB storage or a mix of both; note that 100MB is reserved for the PINN software. 2 Choose your Pi model With the correct media and capacity selected, choose the Raspberry Pi board you’ll be using. Every option is available here, covering A boards, B boards, Zeros and Compute Modules, so choose the correct model with care. There are differences between standard and plus (+) models, so be sure to make the right choice here. If you…

For developers and advanced users, the guix shell command is very useful. The command is an update of the guix environment command. You use this command to create an environment for your applications. However, it’s mostly used for development environments. There are many ways to create development environments, most of them tied to a specific programming language. Python is the best-known example. That system works well for pure Python projects but what happens when you develop web software? You may need JavaScript, Python and a framework. There are solutions for each programming language but with many, it‘s better to create a given environment. With guix shell, you can set all values and revisions. You have the option to take environment variables from the main system or isolate it to many…

Credit: https://getswifty.pro Everybody needs to look after their passwords. The problem is how do you set up a system where each separate account you own is protected by a strong – and unique – password (see the box, opposite) that you can enter easily on demand? You could, of course, write down your passwords in a notebook, relying on an online password generator such as the Secure Password Generator (https://passwordsgenerator.net) to generate those passwords as and when they’re required. The problem is, that notebook will need storing somewhere secure, and flicking through it looking for passwords to type in quickly becomes laborious. The solution is to look for an automated solution that you can access from your PC. This is where the humble password manager comes in. These store all…

With each retro feature we are amazed at how JavaScript – yes that language used to make websites snazzy – can be used to emulate old hardware. The VIC-20 has its own JavaScript emulators and we found www.mdawson.net/vic20chrome/vic20.php which is a full-blown emulator. At a glance this looks rather basic, but click the VIC-20 screen and we go into full-screen mode and start writing BASIC code. Bored of coding? You can load games via the Storage menu. There are a selection of ready-to-go games, or if you wish you can load games via a URL. Try clicking the tape player – it’s a shortcut to loading tape games from URL. This emulator is awesome! We have full control of our virtual VIC-20. We can configure our RAM, model (PAL, NTSC…

Storing large amounts of data on a Linux machine usually means that there’ll come a day when you’ll need to find one particular file out of tens of thousands. No one wants this to be a classical challenge of locating a needle in a haystack, so you’ll need to make use of a search tool. Linux provides several options to choose from, such as the find function, which serves as an old-style tool for continuous searches, together with a variety of tools that can first index your file system and then carry out a much quicker search query based on that index. However, we believe that none of these tools are as flexible and reliable as FSearch. FSearch delivers instant and accurate search results just as you type, with virtually…

There are plenty of ways to find out what the weather’s doing (a legit use of windows–Ed), thanks to all the available meteorological services. But since we’re committed to a nerdy style of doing things – preferably without leaving the terminal window – we’ll check the forecast using a CLI tool. Girouette is a weather application that reports temperature, elements, wind and other usual weather details right inside a Linux terminal. It also does so with style thanks to the built-in support for advanced fonts such as Nerd Fonts. This means that you get full colour support and the feel of a fully fledged GUI weather indicator. Girouette retrieves the information from OpenWeather; it can also automatically guess where you are using Geoclue. You can reveal the exact name of…

Our commitment for efficient data compression know no limits. That’s why we’re so passionate about image encoders such as Lepton (LXF215) and JpegXL (LXF283). Here’s another one called QOI – Quite Okay Image, which has been developed by Dominic Szablewski. QOI is a blazingly fast image encoder that claims to be up to 50 times faster in compression and up to four times faster in decompression compared to the standard Libpng library. The project is in the very early stage of its lifecycle – it’s a proof of concept than a final product – but we can already use it. It all starts with compiling the main executable from the source code: The resulting file will be able to convert existing PNG files to the QOI format, and decode them…

The gorilla/mux package (https://github.com/gorilla/mux) is a popular and powerful alternative to the default Go router. Although there are many differences between the default Go router and the gorilla/mux router, the main one is that gorilla/mux supports multiple conditions when matching a route with a handler function and subrouters. On the other hand, the biggest difference between Gin and gorilla/mux is that gorilla/mux is just an HTTP router and nothing more whereas Gin can do what gorilla/mux can, together with JSON marshalling and unmarshalling, validation, customised response writing and more. In practice, you can consider Gin as being a higher lever framework than gorilla/mux with more capabilities. So, which one should you choose? Why not try both, starting with gorilla/mux. If gorilla/mux can’t meet your requirements, then use Gin. On the…

While we’ve been reporting about an open source revolution sweeping Europe for a while now (see news in LXF68, LXF167, LXF174, LXF222, LXF264 and LXF265), it looks like a German state is planning to make the switch to open source software. As The Document Foundation announced in a blog post (https://bit.ly/lxf285tdf), the state of Schleswig-Holstein, which is in the north of Germany and home to around three million people, is looking to replace Microsoft Office with LibreOffice on all of its 25,000 PCs used by employees and civil servants by 2026. Windows will also be replaced by Linux. In the blog post, The Document Foundation says that “We at The Document Foundation are pleased that LibreOffice is being used in public institutions, and hope that more federal states, governments and other…

New year, new you. At least, that is what New Year Resolutions are supposed to help you achieve. What should you be thinking about in 2022? The first resolution should be to check your bills. Conducting a review of your approach can help you cut down your costs over time. And it should be a regular habit, rather than a one-off. You can find easy ways to improve your performance without resorting to the simple ‘scale by credit card’ approach. Look at what your databases are currently doing, and where you can tweak them to support your workloads more effectively. The best thing here is that you can learn and benefit yourself professionally too. The second resolution? Contribute more to open source communities. There are many ways to get involved…

Mozilla is introducing a new sandboxing tool known as RLBox (read more about it at https://bit.ly/lxf285rlbox) to Firefox 95. Developed with researchers from the University of California San Diego and the University of Texas, RLBox is aimed at making subcomponent isolation easier, which in turn will make using the web browser more secure. Based on WebAssembly, any potential buggy or compromised code can be located and isolated. This could mean that even zero-day vulnerabilities will cause no issues for Firefox. Unlike regular sandboxes used by browsers, RLBox compiles the code into WebAssembly, then compiles that into native code. This prevents the code from accessing other parts of the program, and it can’t access memory outside of what’s been allocated, which should prevent the code from doing any damage. An in-depth…

Virtualisation enables us to set up multiple virtual machines over one physical computer. The benefits of virtualsation are countless, from being able to create virtual representation of different machines, to efficiently use the currently available hardware. Clearly a virtual machine, like any real computer, needs an operating system. In this context it’s called a Guest OS, as opposed to the one running on real hardware, called Host OS. Running graphics applications in a Guest OS can be annoying because they usually hog computing resources, and that can reduce performance. Being able to accelerate all this by offloading the workload to the hardware can be a great benefit. The VirtIO-GPU virtual GPU device comes into play here, enabling a Guest OS to send graphics commands to it using OpenGL or Vulkan.…

The latest set of patches adding Rust support to Linux have been posted by Miguel Ojeda. These include a number of samples that are also intended to serve as CI tests. Among them is a simple character driver. It’s only a matter of time now before Rust becomes supported in the Linux kernel. Chetankumar Mistry posted an interesting RFC (Request For Comments) patch series titled Implement Ziegler-Nichols Heuristic. The algorithm is used for estimating PID (Proportional-Integral-Derivative) controller co-efficients. A PID controller is typically used in a feedback loop to control various systems, such as power and thermal management. In this case, the code aims to improve thermal management within the thermal power governor, which should minimise “the amount of overshoot in the temperature” and throttling. Jessica Yu posted a patch…

We’d love to try and answer any questions you send to lxf.answers@futurenet.com, no matter what the level. We’ve all been stuck before, so don’t be shy. However, we’re only human (although many suspect Jonni is a robot), so it’s important that you include as much information as you can. If something works on one distro but not another, then tell us. If you get an error message, please tell us the exact message and precisely what you did to invoke it. If you have, or suspect, a hardware problem, let us know about the hardware. Consider installing hardinfo or lshw. These programs list the hardware on your machine, so send us their output. If you’re unwilling, or unable, to install these, run the following commands in a root terminal and…

Rsync doesn’t have any specific network backup features, but it could, theoretically, make use of a networked resource (such as an SMB share) as the destination folder, but that could be said of practically any backup software, so it’s a bit of a stretch. All the software suffered from limited cloud support compared to what the underlying backup software is capable of. Deja Dup has reduced its cloud support over the years and now only supports Google Drive. We tried that out and it worked properly, and it was straightforward to set up. Vorta can make local backups or back up onto a Borg server. It’s perfectly possible to host your own Borg backup server, but you need some technical know-how to accomplish this. BorgBase (www.borgbase.com) offers online hosting with…

These days we’re never far from cybercrime-themed headlines. What was very much in the realms of sci-fi a couple of decades ago has become almost commonplace today. In the past few years we’ve seen largescale attacks against Ukraine’s power grid, Sony Pictures, the Colonial Oil Pipeline, JBL-SA(the world’s largest meat supplier) and South African shipping firm Transnet. Such attacks often aim to cause damage and disruption (the power grid attack left hundreds of thousands without power for hours). And sometimes the aim is political. For example, the Sony Pictures hack is widely believed to have originated from North Korea, with hackers demanding The Interview (a Kim Jong Un-themed comedy) be withdrawn. Which it was, although not before gigabytes of embarrassing emails and personal information on Sony Pictures staff was shared.…

Pimoroni’s Display HAT Mini offered a little something extra compared to other screens. Stemma QT is a polarised connector. It only fits in one way, and was created by Adafruit as a smaller version of its Stemma connector. Stemma QT is essentially I2C broken out for use with components modified to use the Stemma QT standard. Sure, we pay a little extra on top of the components base price, but we get the convenience of a single cable and no messy wiring. Because Stemma QT is just I2C we can use the components with other boards, such as Arduino, Raspberry Pi and micro:bit. This can be achieved via a Stemma QT to breadboard cable, or by soldering pins to the components breakout points. In the tutorial we used CircuitPython on…

Released for the Raspberry Pi 3, WD Labs’ PiDrive system married the Pi with a hard disk drive and dedicated cases. There was even a module for attaching a Pi Zero to an HDD, creating an instant server. These devices are long since discontinued, although they appear occasionally on eBay. Their lasting legacy is that they demonstrated how the Pi can be paired with larger, faster storage. As Raspberry Pi 3 was the first model to have the ability to boot from USB (thanks to a complicated and occasionally Pi-breaking process), it made sense that someone should release it alongside a dedicated disk drive. But that wasn’t all it shipped with. While the low-power USB HDD was a key addition, the PiDrive system also required some software. Dedicated versions of…

What constitutes the perfect password? Is it using random characters, the password length or a combination of both? Let’s start with characters. Typing ‘nick’ as your password is clearly weaker than ‘*l3G’ because ‘nick’ is guessable, particularly if it’s your first name. But guess what? A longer – but memorable – passphrase like ‘WindowsSucksUbuntuRules’ is potentially stronger than ‘*l3G’ because while the passphrase might be guessable, it’s more resistant to brute-force attacks, which run through every combination of characters to try and arrive at the correct password. Shorter passwords are therefore easier to crack because there are fewer possible combinations. It’s considered good practice to make passwords at least 12 characters long to tie up brute force attacks for years, but thanks to random password generators, you can easily make…

ISSUE 284 December 2021 Product code: LXFDB0284 In the magazine Discover how to turn your Raspberry Pi into an all-singing, all-dancing media hub. We put a spotlight on video conversion tools, take you on a tour of Stacer, the one-stop system management tool, and emulate the Oric-1 (thankfully without that keyboard). Discover how to build a Pi-powered NAS and learn more on how the world’s top-500 supercomputers all harness the power of Linux. ISSUE 283 December 2021 Product code: LXFDB0283 In the magazine We pit Ubuntu against Fedora to see which is the better Gnome-based distro. Five filesystems are put through their paces, we show how to run a Ghost blog, code a Galaxian-style shooter in Python, and use Okular to edit PDF files with ease. DVD highlights Ubuntu 21.10…

There’s almost no end of audio effects that can be applied to guitars, and many other instruments too. Here are a few others that are commonly considered important parts of the rock musician’s arsenal. Written descriptions don’t do justice to them, though, so do try them out in GNU Radio Companion or Audacity. First up is overdrive and while it might appear to be very similar to fuzz, in that it’s a form of distortion, it’s generally considered to be quite different. As the name suggests, it emulates the effect of driving an amplifier too hard, so it starts to flat-top the waveform. However, it’s not as hard as the clipping in fuzz, so it produces fewer harmonics, and is considered to be a less-aggressive effect. Next we come to…

Newer versions of Linux no longer use the MAC address of a machine to obtain a DHCP address. What this means is that should the administrator (sensibly) configure a base VM and then clone it, the derivative virtual machines will all attempt to claim the same IP address and that’s obviously not an ideal situation. No matter what actions you take (delete network connections, reset the MAC), the problem will still persist. This is because systemd uses the in-built machine-id to identify the machine and this information then gets passed to the dhcpd subsystem and associated tools. Luckily, there’s a way to easily fix this using the netplan configuration file. To remediate it edit the netplan file (sudo nano /etc/netplan/xxx.yaml and add the following line below the DHCP: true line…

The Fediverse is a varied place – not just in terms of users, but of server software, too. The biggest player is Mastodon, created by Eugen Rochko in 2016, and reckoned by many tech publications to be a Twitter killer. Sadly, that never happened, but Mastodon popularised the idea of a decentralised social network, and attracted hundreds of thousands of new users into the Fediverse. Mastodon.social is run by the project developers and hosts around 600,000 users on a single server. Its size makes it unusual on the Fedverse, as most servers tend to have a few dozen or a hundred users at most. In addition to Pleroma/Soapbox (our favourites), Misskey offers a beautiful interface and a treasure trove of fancy features. Note: all of the documentation we were able…