MicroOS Is Immutable Linux

November 14, 2020 by Al Williams 41 Comments

Linux finds a lot of uses in computers that aren’t desktops. But there is a problem. What happens if your mission-critical control computer or retail kiosk gets an update and then fails? Happens all the time with Windows and it can happen with Linux, too. The openSUSE project has an answer: MicroOS which bills itself as immutable. Aimed at container deployment, the operating system promises atomic updates with no disk changes during runtime. If an update does break something, the BTRFS file system allows you to roll back to a previous snapshot. [Tyler] installs the OS and gives it a walkthrough in the video below.

As [Tyler] found, there are not many applications installed by default. Instead, you are expected to install flatpaks so the applications live in their own containers, isolated from the operating system and each other.

Continue reading “MicroOS Is Immutable Linux” →

Linux Fu: Send In The (Cloud) Clones

November 10, 2020 by Al Williams 17 Comments

Storing data “in the cloud” — even if it is your own server — is all the rage. But many cloud solutions require you to access your files in a clumsy way using a web browser. One day, operating systems will incorporate generic cloud storage just like any other file system. But by using two tools, rclone and sshfs, you can nearly accomplish this today with a little one-time setup. There are a few limitations, but, generally, it works quite well.

It is a story as old as computing. There’s something new. Using it is exotic and requires special techniques. Then it becomes just another part of the operating system. If you go back far enough, programmers had to pull specific records from mass storage like tapes, drums, or disks and deblock data. Now you just open a file or a database. Cameras, printers, audio, and even networking once were special devices that are now commonplace. If you use Windows, for example, OneDrive is well-supported. But if you use another service, you may or may not have an easy option to just access your files as a first-class file system.

The rclone program is the Swiss Army knife of cloud storage services. Despite its name, it doesn’t have to synchronize a local file store to a remote service, although it can do that. The program works with a dizzying array of cloud storage providers and it can do simple operations like listing and copying files. It can also synchronize, as you’d expect. However, it also has an experimental FUSE filesystem that lets you mount a remote service — with varying degrees of success.

What’s Supported?

If you don’t like using someone like Google or Amazon, you can host your own cloud. In that case, you can probably use sshfs to mount a file using ssh, although rclone can also do that. There are also cloud services you can self-host like OwnCloud and NextCloud. A Raspberry Pi running Docker can easily stand up one of these in a few minutes and rclone can handle these, too.

Continue reading “Linux Fu: Send In The (Cloud) Clones” →

Linux Fu: Monitor Disks

November 5, 2020 by Al Williams 7 Comments

If you want a quick view of a Linux system’s process load, you can use top or — slightly nicer — htop. But what if you want a quick snapshot of how the disk system is doing? There are a few tools you can use, some of which are not nearly as common as top.

First, iotop

Most similar to top is iotop. This program shows you the total and current disk read and write numbers for the file system and also shows you who is eating up the most disk I/O. This screen looks busy:

Continue reading “Linux Fu: Monitor Disks” →

Linux Fu: Troubleshooting Incron

October 28, 2020 by Al Williams 18 Comments

You probably know about cron, a program that lets you schedule programs to run at various times. We’ve also talked about incron, which is very similar but instead of time, it reacts to changes in the file system. If you ever wanted to write a program that, say, detects a change in a file and automatically uploads it to a programmer, backs it up, e-mails it somewhere, or anything else, then incron might be for you. Although we’ve talked about it before, incron has some peculiarities that make it very difficult to debug problems, so I thought I’d share some of the tricks I use when working with incron.

I was thinking about this because I wanted to set up a simple system where I have a single document directory under git control. Changing a markdown file in that folder would generate Word document and PDF equivalents. Conversely, changing a Word document would produce a markdown version.

This is easy to do with pandoc — it speaks many different formats. The trick is running it only on changed files and as soon as they change. The task isn’t that hard, but it does take a bit to debug since it’s a bit nontrivial.

Continue reading “Linux Fu: Troubleshooting Incron” →

Thinking About Creating A Raspberry Pi Replacement?

October 20, 2020 by Al Williams 66 Comments

If you’ve ever wanted to try your hand at creating a Raspberry Pi-like board for yourself, you should check out [Jay Carlson’s] review of 10 different Linux-capable SoCs. Back in the 1960s, a computer was multiple refrigerator-sized boxes with thousands of interconnections and building one from scratch was only a dream for most people. Then ICs came and put all the most important parts in a little relatively inexpensive IC package and homebrew computing became much more accessible. Systems on Chip (SoC) has carried that even further, making it easier than ever to create entire systems, like the Pi and its many competitors.

Only a few years ago, making an SoC was still a big project because the vendors often didn’t want to release documentation to the public. In addition, most of the parts use ball grid array (BGA) packaging. BGA parts can be hard to work with, and require a multilayer PC board. Sure, you can’t plug these into a typical solderless breadboard. But working with these relatively large BGAs isn’t that hard and multilayer boards are now comparatively cheap. [Jay] reports that he got cheap PCBs and used a hot plate to build each board, and has some sage advice on how to do it.

Continue reading “Thinking About Creating A Raspberry Pi Replacement?” →

Linux Fu: Global Search And Replace With Ripgrep

October 14, 2020 by Al Williams 9 Comments

If you are even a casual Linux user, you probably know how to use grep. Even if you aren’t a regular expression guru, it is easy to use grep to search for lines in a file that match anything from simple strings to complex patterns. Of course, grep is fine for looking, but what if you want to find things and change them. Maybe you want to change each instance of “HackADay” to “Hackaday,” for example. You might use sed, but it is somewhat hard to use. You could use awk, but as a general-purpose language, it seems a bit of overkill for such a simple and common task. That’s the idea behind ripgrep which actually has the command name rg. Using rg, you can do things that grep can do using more modern regular expressions and also do replacements.

A Note on Installing Ripgrep

Your best bet is to get ripgrep from your repositories. When I tried running KDE Neon, it helpfully told me that I could install a version using apt or take a Snap version that was newer. I usually hate installing a snap, but I did anyway. It informed me that I had to add –classic to the install line because ripgrep could affect files outside the Snap sandbox. Since the whole purpose of the program is to change files, I didn’t think that was too surprising, so I did the install.

Continue reading “Linux Fu: Global Search And Replace With Ripgrep” →

Linux Fu: The Linux Android Convergence

October 7, 2020 by Al Williams 63 Comments

The Android phone that you carry in your pocket is basically a small computer running Linux. So why is it so hard to get to a usable Linux environment on your phone? If you could run Linux, you could turn your cell phone into an ultra-portable laptop replacement.

Of course, the obvious approach is just to root the phone and clean-slate install a Linux distribution on it. That’s pretty extreme and, honestly, you would probably lose a lot of phone function unless you go with a Linux-specific phone like the PinePhone. However, using an installer called AnLinux, along with a terminal program and a VNC client, you can get a workable setup without nuking your phone’s OS, or even having root access. Let’s see what we can do. Continue reading “Linux Fu: The Linux Android Convergence” →