ubuntu on Developer's blog

Install Ubuntu on External Disk

Sat, 25 Dec 2021 10:00:00 +0000

Sometimes it can be useful to have an external HDD or SSD with a familiar environment installed. With such a device it’s possible to check the computer from eBay for GPU or memory faults, restore a primary OS of the workstation after an unsuccessful software update or just work on another PC with a familiar OS without any modifications of any software on this machine.

I use Ubuntu 20.04 as a primary OS, that is why in this article, I’ll explain how to install it on an external drive.

Ubuntu periodic tasks

Sat, 17 Jul 2021 06:00:00 +0000

Ubuntu is an open-source system that allows users to control different components. Default desktop installation has a bunch of periodic tasks out of the box. It’s important to understand what is the purpose of these tasks and how often they are called. This knowledge allows to predict the network activity, reduce the number of unexpected CPU spikes and improve user experience. Moreover, some of the default tasks can be redundant for the particular user and that is why should be disabled.

mDNS on Ubuntu Server

Tue, 25 May 2021 03:00:00 +0000

Recently I was configuring a virtual network of several KVM machines for the testing of Gitlab installation. It’s more convenient when I can access machines by hostname but I don’t want to install and support a DNS server. So I’d decided to use mDNS.

Wrong Copying Progress and Long Disk Unmounting on Ubuntu

Mon, 04 Jan 2021 11:00:00 +0000

Sometimes I need to copy files from an internal SSD to an external hard drive. Recently I’ve found a strange behavior on Ubuntu 20.04. When I try to copy a fairly big file (like 2Gb - 4Gb) Nautilus shows insane writing speed and the progress bar instantly reaches 100%, but when I want to unmount the device - it freezes for several minutes. I tried different file managers like Thunar from Xfce, midnight-commander, or even utilities like rsync or pv - the result was the same. For me, it’s a bit inconvenient when I don’t know how much time I have to wait until all data will be transferred, so I tried to find the solution to this problem.

Ubuntu Snap: the Price of the Isolation

Sat, 12 Sep 2020 06:00:00 +0000

The idea of the majority of Linux distributions is to compile Linux kernel, collect existing Open Source and proprietary software, test and then patch it if required, add something own and pack the results into the packages, so users can install and use these programs. Ubuntu packages grouped into APT repositories. Users can manage packages with apt command.

Software developers usually do not write all the code required by their programs, but use different libraries and frameworks (e.g. graphical applications can use GTK to draw widgets like button or label). It allows developers to save some time and make fewer bugs. As a result the majority of software nowadays has dependencies. Different programs can depend on the same library (most of the GUI programs in Gnome depend on GTK) that is why there is no need to install the same library several times. Each APT package defines a list of dependencies, so when the user executes a command like apt install gnome-calculator package manager install not only gnome-calculator itself but also its dependencies like libgtksourceview-4-0.

Such an approach allows users to save disk space and reduce security risks: if there is some problem in the common library it’s enough to update it once and all dependent programs will use the new version. Unfortunately, such an approach is not a silver bullet and has some downsides:

Suppose two programs depend on different versions of the same library. It this case there will be a conflict during dependencies resolution that is why apt command will fail and the user can’t install both programs at the same time.
Providers of third-party software like Viber or Skype have to make different packages of the same product for different Ubuntu distributions, e.g. 18.04 and 20.04 have different versions of system libraries that, so it’s required to build and maintain two different packages for one program.
apt installs each program globally so it will be a conflict when two packages try to create a file with the same name.
Traditional programs can access all user files and resources that is why it’s difficult to control such software. In case of a security vulnerability in one program all user’s files are in danger.

Several years ago Ubuntu introduced Snap - a package manager with an alternative approach, designed to solve apt problems.