Prototype700's questions

I would like to install Ubuntu on a two-disk RAID 1 with dm-integrity and LUKS2-encryption.

Unfortunately, neither Ubiquity, nor the alternative textmode-installer offer such a solution.

Although this seemed simple to do manually, I haven't been able to install the system, yet.

The layout for both drives was as follows:

1. /dev/sdX1 [ext2] to be used as unencrypted /boot
2. /dev/sdX2 [unformatted] to be configured in LVM for encrypted /root & swap

I formatted both drives on a live system in gparted and then executed cryptsetup luksFormat --type luks2 --integrity hmac-sha256 /<device>/<partition> for either drive as a basis in order to create the RAID device, LVM and filesystem on top of later in the manual installer.

However, the manual partitioner does not recognise the encrypted partitions and I can't continue to work with them.

How can I "open" the encrypted partitions to set them up for the system installation without re-formatting them first?

Is there anything else that needs to be considered with this approach? Does Ubuntu demand certain LUKS-parameters or is something advisable to use for this purpose?

Do I have to manually add the devices to a file after the installation to be corrctly decrypted at boot? Is the --integrity option used automatically?

Is this even the best approach or is there another way to accomplish this? (Excluding the usage of Btrfs/ZFS filesystems)

I've installed Ubuntu 20.04 on a Btrfs root-partition for its snapshot functionality.

To keep it as simple as possible, I would like to integrate the creation of a Btrfs snapshot into my upgrade-alias command, which currently looks like this:

sudo apt update && sudo apt upgrade -y && sudo flatpak update -y && sudo snap refresh

How would I best add a snapshot before the updates so I can roll back if anything goes wrong?

Is there also a possiblity to remove older snapshots at the same time? (My root-partition is filled less than 10%, so I could copy my entire system multiple times, but I suppose it will fill up quickly with weekly updates?)

Like many smaller machines, my laptop's keyboard is missing a dedicated numpad.

I can generally type without looking at my keyboard, but I am unable to blindly type numbers with the number row. That's why I thought of converting the left side of my keyboard into a second-level numpad (e.g. Z = 0, X = 1. C = 2, V = 3, S = 4 and so on).

Another advantage would be the possiblity to quickly type numbers without taking the right hand off the mouse or moving the left hand across the entire keyboard.

Now I'm looking for a way to remap those keys to "create" the numpad, at best independent of the desktop environment, as I'm using multiple ones constantly. Also, it would be amazing if that mapping was portable, so I could set it up once and enable it for different keyboards/machines.

I know that it's possible to modify the keymap directly inside /usr/share/X11/xkb/symbols/, but those allow only three modifiers (Shift, AltGr (on European keyboards) and Shift + AltGr) and they're usually in use on the letter keys or require both hands to activate.

I thought of using either Super_L or a combination of Shift_L + Alt as modifier keys to access the numpad layer, since those combinations shouldn't be in use and are easy to reach with one hand.

How could this be accomplished?

One of the promoted advantages of Snap packages is the sandboxing-feature, where a Snap program may not be able to access as much system information as a package from the repository.

Now, I have read a lot about permission problems with Snap software and how to fix them, but I don't know where to find actual information on what permissions a specific Snap package has.

The Snapcraft-website is also very brief about this.

As one concrete example: How can I find out what permissions the Discord Snap gets and (how) am I able to modify those permissions to basically only allow Pulseaudio/microphone access? (Because that's all it needs to have.)

I have a rather specific issue and can't solve it on my own.

As explained in this Question, I have set up a system-wide volume control for my single USB audio card (M-Audio Fast Track). Now, I would also like to add a system-wide equalizer (libasound2-plugin-equal) to it, while keeping the volume control intact.

So far, I was able to get everything working correctly only in ALSA-programs.

With the following /etc/asound.conf, both the volume-control via softvol and the equalizer settings work at the same time:

pcm.!default {
        type plug
        slave.pcm "softvol"
}

ctl.!default {
        type hw
        card Track
}

pcm.softvol {
        type softvol
        slave {
            pcm "hw:Track"
        }
        control {
            name "Master"
            card Track
        }
}

ctl.equal {
        type equal;
}

pcm.plugequal {
        type equal;
        slave.pcm "plug:softvol";
}

pcm.!default {
        type plug;
        slave.pcm plugequal; 
}

Source: https://docs.slackware.com/howtos:hardware:sound_problems_on_slackware

There seems to be some redundancy, but this is the setup that works currently.

The issue that remains now is that PulseAudio apparently skips all of this setup and directly outputs to my sound card, so the equalizer works in programs that support ALSA-output (not Firefox, etc.) and JACK, since the output device can be specified.

Does someone know how to isolate PulseAudio in such a way that it will only output to the plugequal ALSA-device and not be connected to my sound card directly?

Unfortunately, PulseAudio doesn't list plugequal as an output device, just my hardware sound card.

I have uninstalled PulseAudio at the moment, since it disables the EQ and volume control when it is connected to the sound card.

I would like to use Btrfs on two mirrored drives (RAID 1), used for archive data on a desktop system (media files, etc.), for redundancy/availability and potential self-healing functionality in case of a drive failure.

This implies that I don't want any additional (server-oriented) functionality, such as deduplication, file compression or ARC on the filesystem, which should reduce the resource demands on a regular desktop system with more limited CPU and RAM headroom, compared to NAS or server systems.

How do I correctly setup Btrfs with the core functionality and none of these additional, more demanding features on a recent Ubuntu system (18.04+)? What else could be configured to reduce the consumption of system resources?

I have read various guides and think I know how to install Btrfs and that most of these features are not enabled by default, but since a correct initial setup is very important in this case, I would like to make absolutely sure there are no misunderstandings or differences in the Ubuntu-specific setup.

Detailed questions:

1. Is it enought to install btrfs-tools to set this up or is something else needed, also for scrubbing and defragmentation?

2. You mention that the disks can be used with or without partitions, what are the (dis)advantages of either option?

3. Do you happen to know whether any kind of (L2) adaptive replacement cache is being used by default? (I would rather defragment regularly instead of setting aside RAM for it.)

4. You wrote that lzo-compression will increase (read/write?) speeds, without going into too much detail, how does this work?

I have a bit of a specific question:

Being a musician, I use Ubuntu for software monitoring and I would like to control my output master volume with my mouse wheel.

For this purpose, I currently use EasyStroke with the commands amixer -D pulse sset Master 5%+ (Mouse wheel up) and amixer -D pulse sset Master 5%- (Mouse wheel down), which works fine.

The problem is that I use some programs that have a direct JACK output, such as Reaper, my DAW, and also some media players.

As long as the software uses the PulseAudio JACK Sink output, I can control the output volume via mouse wheel, but when the software does not use PulseAudio, it is directly connected to JACK and always at max volume.

If you refer to the screenshot: I am able to manipulate the master volume of the red-marked output (PulseAudio JACK Sink), but I actually need to access the one marked green to control all sound (system out).

Unfortunately, I can not control my ALSA master volume via amixer -q sset Master X, because ALSA does not offer any controls for my only USB sound card.

Is there any way to control the JACK Output volume via terminal that I could replace my mouse button commands with?

Or alternatively, is there a way to add a PulseAudio input module to the right side of the JACK connections to connect Reaper and all other JACK software and route them through the PulseAudio JACK Sink? (PulseAudio JACK Source is only used for microphones and won't play back the input.)

When installing the linux-lowlatency package on 18.04 LTS, the lowlatency-kernel version 4.15 is installed, while the -generic kernel has been updated to 4.18 since the LTS release.

4.18 linux-lowlatency packages are only available for cosmic and later releases.

Is there any way to automatically get new lowlatency-kernel versions on 18.04?

In Ubuntu 18.04.1, I would like to use my left Super-key only to simply open the Show Applications menu (aka Dash) like a left click on the dock-icon (with the 9 dots) does and preferably close it again without showing me any open programs.

I can open it with Super + A and even close it again with Super R, but Super L appears to do nothing at all.

In Xfce, something similar was possible by adding a custom keyboard shortcut for Super L and setting the command to xfce4-popup-whiskermenu, which would open and close a menu with favourite applications. Unfortunately, I don't know the command that opens and closes the Show Applications menu.

Is there any way to add such a shortcut in the new Gnome Shell?

I am working on the front-end of a website and need to see how my code behaves in different systems/browsers. Firefox and Chromium do have development tools that allow the display to be set to different sizes, but they are unable to fully emulate Apple's upscaling mechanism and the sites will still look slightly different. Also they don't take into account different browsers.

Is there any tool or software I can use with Ubuntu to check what my site will look like on different devices/browsers?

Having used Windows systems for a long time, I know that at a certain point, an error window can appear when files and folder names become too long.

This happened to me when I tried to backup files with SFTP from a server to a folder in (for example):

D:(Windows drive partition)/Temporary/Projects/2015-06/Websites/Guitar-Site/Images/Logos/Manufacturers/Instruments/Basses/(long file name).png

As you can see, I tend to build very specified folder paths sometimes and if a file name happens to be long as well, NTFS might not be able to save it this way.

I'm currently worrying about my physical backups, as the folder path on my backup drive will add /backups/(drive name)/... to all file paths.

Is there any such limit (or a similar one) in ext4/Ubuntu that I would have to look out for?

The wheel-button on my mouse appears to be malfunctioning, but the mouse itself, including the wheel, is still fine.

Is there any possibility to assign the "middle-click"-function to something like both traditional buttons being pressed at the same time?

I am constantly using multiple workspaces for different types of programs and I would like to have them all visible on my Xfce Panel.

The "tasklist" plugin has the option to show open tabs from all workspaces, but it does not organise them in any way, so just by looking at it, I don't know what program is openend on which workspace.

Then, I recently saw this screenshot:

After testing all available plugins, I found out that the "windowmenu" can show all tabs sorted by workspaces, just like the Panel in the screenshot. However, it only does this after pressing a button that has to be added to the Panel first.

How can I have my Panel show open tabs similar to the one in the screenshot? (It does no have to reserve space for all workspaces, just sort them by which virtual desktop they're on.)

Recently, I needed to test various kernel boot-options with a live system and had to install a program to check system information on every boot (I did not have a USB drive available and the CD was the more reliable choice at that moment).

After a handful of installations, I began to wonder, where the program is actually "saved", since the CD does not have a persistent area and it's also possible to create USB drives without one. Also, it's possible to download files or make screenshots with a non-persistent live system and temporarily save them in the user directories.

Where are these files actually saved? Are they loaded into the RAM, so the maximum available memory for the live system is actually the RAM capacity of the machine? Are installed programs stored in the CPU cache or somewhere else entirely? Or is that information possibly written on empty space of the CD medium? It obviously can't be unallocated hard drive space, since live systems also work with fully encrypted or even completely without hard drives installed.

On Windows, I have used the program 7zip for nearly all of my compression tasks in the past. Now, after switching to Ubuntu, I also installed this program from the Software Center. After completion, I was able to select the .7z-format from the archive-creation menu, however I can not find any compression options, just the possibility of encrypting the file table and a password prompt. In the Windows build of the program, there are many more options, such as library size and thread usage, but I have not yet been able to find such a menu in Ubuntu.

Is there a way to make these options available in the integrated archive manager or an alternative one that provides them?

I am aware that it is possible to define these options in the terminal, but I would prefer to have an interface that lets me see all possible choices and interactively calculates memory usages.

If another library than 7zip offers these options under Ubuntu, I would be willing to try that one, as long as it is F/OSS. Platform compatibility is not impotant, just quickly selectable options for different tasks.

I'm planning to install a new Ubuntu system on an empty hard drive with more than 3TiB of volume. In order to fully utilize the drive, the regular MBR partition table can not be used.

How do I set up a GPT partition table in the Ubuntu installation? The manual installation option only offers ways of setting up certain partitions, not a general partition table, if I am not mistaken. How do I make sure that the installer will not use the usual MBR partition table?

Although my motherboard uses UEFI, there is no special reason for me to use another bootloader than the regular grub that I am aware of (except if it is easier to install on a GPT drive or significantly faster/more advanced). All guides I have found so far focus mainly on the mechanics of U/EFI boot.

What steps do I have to take to basically set up a regular manual Ubuntu installation, but with a GPT partition table instead of MBR/grub? I assume the selection for the bootloader installation is also different in this case?

As I understand, Compiz can be installed as the compositing-manager on various desktop environments. I am using Ubuntu Studio 15.10 with Xfce 4.12 and I want to install Compiz in its basic configuration just to use simple fading, shadows and maybe the infamous Cube workspace-switcher, however I would like the visuals of my windows to stay as they are.

So far, I have only found old tutorials on how to install Compiz on Xfce that are sometimes dated multiple years back and often involve adding additional PPAs or plugins and applications that I do not want to use or can not understand the use of.

Is it possible to just install and use the Compiz version from the Ubuntu Software Center to get what I am looking for? Or will I still need some additional software to make it compatible to Xfce?

It would be great if someone could explain a current way of installing just the basic Compiz functionality or point to an up-to-date website which explains this.

In some programs like SMPlayer and Clementine when dragging the window with the mouse (for example by accidentally clicking on the program window instead of the media progress bar), the mouse pointer freezes in the dragging-hand state and does not return to the normal cursor when releasing the left mouse button. The keyboard will not take any input at this state, either.

When reacting qickly to this and pressing Control+Alt+F1, it is possible to enter the non-GUI logon screen, enter the username and password and restart lightdm with sudo service lightdm restart. Else, the system will completely freeze and must be resetted manually.

This only appears to happen in programs that use the classic NT-style windows, such as the mentioned SMPlayer and Clementine (unsure).

What could be the reason for this and is there any way to solve this problem or to release the drag?

To reproduce: Start Ubuntu Studio (/Xubuntu?), install SMPlayer and/or Clementine out of the Software Center and drag the window near the media progress bar on the bottom of the screen.

If Canonical removes a program from the repositories of the Ubuntu Software-Center, what exactly happens to my installation?

I like using the Software-Center to easily find and install programs on Ubuntu and to manage updates so that the software is always on the latest version. As an example, I'm using the program MediaInfo (for no particular reason). MediaInfo changed their licensing from LGPL to FreeBSD recently: While it is still FOSS, it may be possible that the program (or any other program out of the Software-Center) gets bought by a company that applies a proprietary license or adds other functionality that does not agree with the terms of the Ubuntu software repositories made available to the users in the Software-Center.

In this case, it will likely be removed from the Software-Center, if I understand it correctly. What will happen to the program on my computer, if I already have installed it at that point?

Will it automatically be removed from my system? Will it just not be updated to the next version? Will the last appropriate version still remain available in the Software-Center? And will I receive some kind of notification about any of this?

My aunt needs a new laptop and I'm planning to buy one for her and set it up with Xubuntu. She has been using Windows 7 so far, mostly for internet and office work. However, she has developed a certain... addiction to the stock Windows 7 Solitaire game.

When I set up her new computer, I want to install a Solitaire game for her that is as similar as possible to the Windows 7 game. Unfortunately I have never played Solitaire before and do not even have a computer at hand to compare the games.

Does someone have an idea of which game I could install for her out of the Ubuntu Software Center? (I don't want to add potentially unsafe PPAs) It should just be really simple and not have too many options and game modes, because that might even confuse her.

Thank you in advance and kind regards!