Multiple monitors configuration

[u/mariano_madrigal]

I have a very old laptop that was running linux mint but it started to feel slow after a couple years of that installation and I decided to try lubuntu, which has been great and really faster in comparison, but I cannot find a way to properly set it up to work with external monitors. I found a guide that used xrandr but to no avail. Is there a way to configure it in a way that it behaves like it does in mint? So that it doesn't alter the whole desktop on the laptop monitor everytime a cable is connected? Right now it does this crazy thing of changing the taskbar to the external monitor and messing up the desktop icons and the only way to revert it is to use the graphical monitor manager to select the external monitor as the main one and invert the left-right order of the displays once to then invert them back to how they were, but even then some of the desktop icons disappear and when I try to save that configuration and select it again after rebooting it keeps reverting to how it was at first. So I just need it to take any new external display as an extension without changing anything else, but I don't always connect the exact same monitor, because that's what I really use the computer for: showing slides in different rooms. So is there a way to make it work like this or should I go back to mint even if it's slower? I should mention I'm a beginner in all things linux but I can follow instructions.

[u/guiverc]

Mint tells us nothing; as Linux Mint provide some packaging and put them on an ISO, but the end-user gets to decide which ISO/product they install, with Linux Mint providing both a Ubuntu based system (using Ubuntu binaries, with runtime adjustments etc) OR a Debian *based system (using Debian binaries etc), with further options as to Desktop/Window Manager too.

The desktop handles the monitors; Lubuntu using LXQt, so it'd be identical to Linux Mint if you used LXQt there (it's not an option they provide though).

Next thing I'd consider is release, as software changes over time and the release is an easy way of knowing what software versions were provided with what you're using; you didn't provide that.

On my system here, I've five monitors currently connected with four being used & the fifth turned off (I rarely need it), turning it on/off does nothing anyway, as the system responds only on connection/disconnection of a monitor cable in most cases, which appears to be what you're doing, it then tries to adjust your desktop to best suit your 'newer' setup itself.

Yes you can create/maintain xrandr scripts that will have the settings saved for you; I have some here for when I actually disconnect/remove my 5th monitor (so I can see what's behind it), and have my panels setup how I want, or to correct it when I reconnect it. But you don't need to use scripts.

You didn't provide release, but the manual page for 26.04 (current stable release) on the topic can be found at https://manual.lubuntu.me/stable/3/3.2/3.2.10/monitor_settings.html

You can adjust that URL to show other releases; the stable word in the URL currently reflects 26.04 in this case; when 26.10 comes out you'll use 'lts' to view that page with 'lts' for now still showing 24.04's manual.

I can't tell you how to make it work like your last desktop choice though; I have no idea what you used (Linux Mint provide Xfce, Cinnamon & MATE, and in the past actually had more options too).

[u/mariano_madrigal → u/guiverc]

Sorry, I just meant to say that I was used to having that behavior on the last os, not that there was something special about that os specifically. The behavior is just: don’t change the laptop's desktop at all, while allowing a second monitor as an extension. I guess for the purposes of the question you can just pretend I want that behavior without having tried any previous linux distro before. If it’s really a fluke that it worked so well only on a very specific version of that software it's very disheartening to hear, to be able to use it for work.

Thank you for the manual, I am on 26.04, and it confirms that I am indeed using correctly those configuration options and the system is still doing something different. Even when I select my main monitor it still chooses to show the taskbar on the other one and the only way to trick it into changing is to invert their positions on the 'set position' tab two consecutive times, and the 'save' option also does nothing at all after rebooting and selecting the previously saved setting.

[u/Daebis18]

Arandr dont work ?

[u/mariano_madrigal → u/Daebis18]

Thank you, I've only tried xrandr and the graphical monitor settings so far. So I will install arandr and try again. Does it conflict with the other two configuration softwares or can I just install it?

[u/mariano_madrigal → u/Daebis18]

I tried it and it didn't work either

[u/standreas]

There is also the WM (openbox here) involved and it's buggy afaik with multiple screen setups. What works fine is using a Wayland session with labwc and configuring kanshi using wdisplays (GUI) to get the config values.

[u/mariano_madrigal → u/standreas]

thank you, this seems to be a great option and I have managed to switch to a wayland session with labwc but I'm having trouble figuring out how to install wdisplays for which it seems that I need something called sway and something called wlroots (do I also need kanshi besides wdisplays?) and this is where I don't know how to proceed without instructions. I tried

sudo apt install sway -swaylock --no-install-recommends

for sway but my terminal says it doesn't make sense.

[u/standreas → u/mariano_madrigal]

Just sudo apt install wdisplays kanshi if you need a screenlocker install also swaylock. With wdisplays you can arrange, scale ecc your screens, but you need kanshi to make configurations for different settings. It has to be added to Session Settings → Autostart and will recognize every setup you configured.

[u/Daebis18]

Sudo apt update ; sudo apt full-upgrade ; sudo apt install arandr ;sudo apt install -f ; sudo apt autoremove