Questions[multiseat](ubuntu)

I've been reading (old) guides all day and I still know nothing about multiseat on Ubuntu 18.04. To make matters worse, I only have one graphics card with multiple outputs.

The only thing that gives me hope is loginctl list-seats which indicates that my Ubuntu knows about seats.

How can I set up my machine in multiseat?

Edit: output of loginctl commands.

Please note that not everything is connected. I want to first figure out how to get about it, not just plunge in. I figure each seat will have its own USB hub (HID devices + whatever else needed) + one of the displays.

loginctl list-seats
SEAT            
seat0           

1 seats listed.

loginctl seat-status seat0

seat0
Sessions: *c1
 Devices:
      ├─/sys/devices/LNXSYSTM:00/LNXPWRBN:00/input/input1
      │ input:input1 "Power Button"
      ├─/sys/devices/LNXSYSTM:00/LNXSYBUS:00/PNP0C0C:00/input/input0
      │ input:input0 "Power Button"
      ├─/sys/devices/pci0000:00/0000:00:01.3/0000:03:00.0/usb1
      │ usb:usb1
      │ ├─/sys/devices/pci0000:00/0000:00:01.3/0000:03:00.0/usb1/1-12/1-12:1.0/input/input11
      │ │ input:input11 "iMON USB Touchscreen (15c2:0034)"
      │ ├─/sys/devices/pci0000:00/0000:00:01.3/0000:03:00.0/usb1/1-12/1-12:1.0/input/input2
      │ │ input:input2 "iMON Panel, Knob and Mouse(15c2:0034)"
      │ └─/sys/devices/pci0000:00/0000:00:01.3/0000:03:00.0/usb1/1-12/1-12:1.0/rc/rc0/input3
      │   input:input3 "iMON Remote (15c2:0034)"
      ├─/sys/devices/pci0000:00/0000:00:01.3/0000:03:00.0/usb2
      │ usb:usb2
      ├─/sys/devices/pci0000:00/0000:00:03.1/0000:26:00.0/drm/card0
      │ [MASTER] drm:card0
      │ ├─/sys/devices/pci0000:00/0000:00:03.1/0000:26:00.0/drm/card0/card0-DP-1
      │ │ [MASTER] drm:card0-DP-1
      │ ├─/sys/devices/pci0000:00/0000:00:03.1/0000:26:00.0/drm/card0/card0-DP-2
      │ │ [MASTER] drm:card0-DP-2
      │ ├─/sys/devices/pci0000:00/0000:00:03.1/0000:26:00.0/drm/card0/card0-DP-3
      │ │ [MASTER] drm:card0-DP-3
      │ ├─/sys/devices/pci0000:00/0000:00:03.1/0000:26:00.0/drm/card0/card0-DVI-D-1
      │ │ [MASTER] drm:card0-DVI-D-1
      │ └─/sys/devices/pci0000:00/0000:00:03.1/0000:26:00.0/drm/card0/card0-HDMI-A-1
      │   [MASTER] drm:card0-HDMI-A-1
      ├─/sys/devices/pci0000:00/0000:00:03.1/0000:26:00.0/drm/renderD128
      │ drm:renderD128
      ├─/sys/devices/pci0000:00/0000:00:03.1/0000:26:00.1/sound/card0
      │ sound:card0 "NVidia"
      │ ├─/sys/devices/pci0000:00/0000:00:03.1/0000:26:00.1/sound/card0/input12
      │ │ input:input12 "HDA NVidia HDMI/DP,pcm=3"
      │ ├─/sys/devices/pci0000:00/0000:00:03.1/0000:26:00.1/sound/card0/input13
      │ │ input:input13 "HDA NVidia HDMI/DP,pcm=7"
      │ ├─/sys/devices/pci0000:00/0000:00:03.1/0000:26:00.1/sound/card0/input14
      │ │ input:input14 "HDA NVidia HDMI/DP,pcm=8"
      │ └─/sys/devices/pci0000:00/0000:00:03.1/0000:26:00.1/sound/card0/input15
      │   input:input15 "HDA NVidia HDMI/DP,pcm=9"
      ├─/sys/devices/pci0000:00/0000:00:07.1/0000:27:00.3/usb3
      │ usb:usb3
      ├─/sys/devices/pci0000:00/0000:00:07.1/0000:27:00.3/usb4
      │ usb:usb4
      ├─/sys/devices/pci0000:00/0000:00:08.1/0000:28:00.3/sound/card1
      │ sound:card1 "Generic"
      │ ├─/sys/devices/pci0000:00/0000:00:08.1/0000:28:00.3/sound/card1/input10
      │ │ input:input10 "HD-Audio Generic Front Headphone"
      │ ├─/sys/devices/pci0000:00/0000:00:08.1/0000:28:00.3/sound/card1/input4
      │ │ input:input4 "HD-Audio Generic Front Mic"
      │ ├─/sys/devices/pci0000:00/0000:00:08.1/0000:28:00.3/sound/card1/input5
      │ │ input:input5 "HD-Audio Generic Rear Mic"
      │ ├─/sys/devices/pci0000:00/0000:00:08.1/0000:28:00.3/sound/card1/input6
      │ │ input:input6 "HD-Audio Generic Line"
      │ ├─/sys/devices/pci0000:00/0000:00:08.1/0000:28:00.3/sound/card1/input7
      │ │ input:input7 "HD-Audio Generic Line Out Front"
      │ ├─/sys/devices/pci0000:00/0000:00:08.1/0000:28:00.3/sound/card1/input8
      │ │ input:input8 "HD-Audio Generic Line Out Surround"
      │ └─/sys/devices/pci0000:00/0000:00:08.1/0000:28:00.3/sound/card1/input9
      │   input:input9 "HD-Audio Generic Line Out CLFE"
      └─/sys/devices/virtual/misc/rfkill
        misc:rfkill

I have created a multi seat Ubuntu 16.04 and separated the devices to two seats.

I was able to login to the first seat i.e., seat0 without any issues do the work in it.

While coming to second seat i.e., seat1 i am not able to login and it is showing as Retry "Failed to authenticate" for every user. but with the same user i am able to login in seat0.

Please help us or guide resolve the above issue.

Thanks in advance.

I'm trying to use multiseat with Ubuntu, but I can't make this work.

I've read a lot of "how to", and the most of them are about doing a multiseat with some distro with GDM2, or KDM. But, I'm using the lightdm of Ubuntu.

So now I'm trying to make this multiseat with Xephyr, which I've already used to make a multiseat with the Debian 4 version. But I don't know how to call Xephyr in lightdm.conf.

I have a multiseat Ubuntu setup and I need to identify which processes of a graphical application are running in each X.Org display.

For example, I have two X.Org displays, :0 and :1, and two instances of Firefox running, one on each display. How do I find the PIDs of the processes of Firefox running on display :0 only?

Neither ps -e nor ps -T helped me. In both cases, I have a single "?" in TTY column for my Firefox processes.

I've asked about multiseat before. The answer (for 10.04) involved doing it the proper way (eg through gdm, multiple server layouts). The problem was that gdm needs to be patched or reverted to 2.20 for multiseat. It's an ugly hack that, worse than anything, will hold up future updates.

As a result, I didn't do anything. I still have a spare video card. I still have the monitor, keyboard and mouse all sitting waiting to jump into action. And I still want to be able to turn that into a simple desktop.

My needs don't seem complicated. I have a second video card, a USB hub and anything connected to that USB hub that I want to be dedicated to another X server. I don't need a login screen (I'm happy hard-coding in a auto-login and I'd be happy with the user starting the X server if that's possible).

This is so simple in my head that I only need two questions:

1. How can I explicitly start an X server from the command line on an unused video adapter (by passing it whatever configuration I need to)?

2. Can I have this new X session load a desktop environment on load?

This seems like something you should be able to write in a little upstart script within 10 minutes. That would be perfect for me as then I'd have a nice start/stop control over the secondary desktop from the main desktop (that I want to leave unscathed!)

I'm thinking something as simple as this for the payload:

su -u other_user -c "startx -- localhost hardware-information"

And use .xinitrc to load openbox or something...