Systemd Gets Generic Multi-Session, Session Devices

[phoronix]

Phoronix: Systemd Gets Generic Multi-Session, Session Devices

The logind component of systemd now has support for "session devices" and generic multi-session handling as part of the work done by CONFIG_VT-killer David Herrmann...

http://www.phoronix.com/vr.php?view=MTQ2NDQ

[xeekei]

I'm unsure what this means...?

[Teho]

I'm unsure what this means...?

The developer made quite a few blog posts about the subject:

http://dvdhrm.wordpress.com/2013/08/24/session-management-on-linux/

http://dvdhrm.wordpress.com/2013/08/24/how-vt-switching-works/

http://dvdhrm.wordpress.com/2013/08/25/sane-session-switching/

http://dvdhrm.wordpress.com/2013/07/08/thoughts-on-linux-system-compositors/

[drag]

I'm unsure what this means...?

Linux VT = Linux virtual terminal. Also called virtual console.

http://en.wikipedia.org/wiki/Virtual_console

When you hit ctrl-alt-F1 you switch to the first virtual console. Hit ctrl-alt-F2 you switch to the second and so on and so forth for all the different F keys.

Each virtual console then runs a console output. It can be X Windows, standalone GL graphics, VGA text console, FBdev text console, and other such things.

Typically you have 1 X windows console and then 6 or 7 text consoles configured by default. The text consoles are controlled by a program called a 'getty' and the X11 console is controlled by your X Windows Server.

like this:
root@machinename:~# ps -ef|grep getty
root 3885 1 0 03:08 tty1 00:00:00 /sbin/getty 38400 tty1
root 3886 1 0 03:08 tty2 00:00:00 /sbin/getty 38400 tty2
root 3887 1 0 03:08 tty3 00:00:00 /sbin/getty 38400 tty3
root 3888 1 0 03:08 tty4 00:00:00 /sbin/getty 38400 tty4
root 3889 1 0 03:08 tty5 00:00:00 /sbin/getty 38400 tty5
root 3890 1 0 03:08 tty6 00:00:00 /sbin/getty 38400 tty6
root 10541 4589 0 06:32 pts/0 00:00:00 grep getty


TTY is just the traditional name for text console. It's a throw back to the ancient days when all we had were serial consoles to big machines.

http://en.wikipedia.org/wiki/Teleprinter

http://en.wikipedia.org/wiki/VT100

Traditionally you had F1-F7 virtual consoles controlled by a getty and then F8 was your login for X Windows. However Fedora systems and a couple others have moved to having F1 being X. But you can configure them to be anything you want, really. A lot of time Linux installers, for example, will have the installer run on F1, have a root shell on F2 and F3, and have various logging information showing on F4 and F5.

Right now if you want real multi user sessions in Linux you have to depend on hacks with X windows or you have to switch back and forth using ctrl+alt+F* and have the Linux kernel control it.

They want to move away from that because it causes usability and/or performance issues. They want to have the ability for more flexible multiuser configuration setup.

[FourDMusic]

The developer made quite a few blog posts about the subject:

http://dvdhrm.wordpress.com/2013/08/24/session-management-on-linux/

http://dvdhrm.wordpress.com/2013/08/24/how-vt-switching-works/

http://dvdhrm.wordpress.com/2013/08/25/sane-session-switching/

http://dvdhrm.wordpress.com/2013/07/...m-compositors/

These articles are excellent. Highly recommend reading them.

[Sonadow]

Linux VT = Linux virtual terminal. Also called virtual console.

http://en.wikipedia.org/wiki/Virtual_console

When you hit ctrl-alt-F1 you switch to the first virtual console. Hit ctrl-alt-F2 you switch to the second and so on and so forth for all the different F keys.

Each virtual console then runs a console output. It can be X Windows, standalone GL graphics, VGA text console, FBdev text console, and other such things.

Typically you have 1 X windows console and then 6 or 7 text consoles configured by default. The text consoles are controlled by a program called a 'getty' and the X11 console is controlled by your X Windows Server.

like this:
root@machinename:~# ps -ef|grep getty
root 3885 1 0 03:08 tty1 00:00:00 /sbin/getty 38400 tty1
root 3886 1 0 03:08 tty2 00:00:00 /sbin/getty 38400 tty2
root 3887 1 0 03:08 tty3 00:00:00 /sbin/getty 38400 tty3
root 3888 1 0 03:08 tty4 00:00:00 /sbin/getty 38400 tty4
root 3889 1 0 03:08 tty5 00:00:00 /sbin/getty 38400 tty5
root 3890 1 0 03:08 tty6 00:00:00 /sbin/getty 38400 tty6
root 10541 4589 0 06:32 pts/0 00:00:00 grep getty


TTY is just the traditional name for text console. It's a throw back to the ancient days when all we had were serial consoles to big machines.

http://en.wikipedia.org/wiki/Teleprinter

http://en.wikipedia.org/wiki/VT100

Traditionally you had F1-F7 virtual consoles controlled by a getty and then F8 was your login for X Windows. However Fedora systems and a couple others have moved to having F1 being X. But you can configure them to be anything you want, really. A lot of time Linux installers, for example, will have the installer run on F1, have a root shell on F2 and F3, and have various logging information showing on F4 and F5.

Right now if you want real multi user sessions in Linux you have to depend on hacks with X windows or you have to switch back and forth using ctrl+alt+F* and have the Linux kernel control it.

They want to move away from that because it causes usability and/or performance issues. They want to have the ability for more flexible multiuser configuration setup.

I learnt something new today.

[plonoma]

Linux VT = Linux virtual terminal. Also called virtual console.

Traditionally you had F1-F7 virtual consoles controlled by a getty and then F8 was your login for X Windows. However Fedora systems and a couple others have moved to having F1 being X. But you can configure them to be anything you want, really. A lot of time Linux installers, for example, will have the installer run on F1, have a root shell on F2 and F3, and have various logging information showing on F4 and F5.

Right now if you want real multi user sessions in Linux you have to depend on hacks with X windows or you have to switch back and forth using ctrl+alt+F* and have the Linux kernel control it.

They want to move away from that because it causes usability and/or performance issues. They want to have the ability for more flexible multiuser configuration setup.

That's horrible! Good thing somebody is working on fixing that.

[Marc Driftmeyer]

Linux VT = Linux virtual terminal. Also called virtual console.

http://en.wikipedia.org/wiki/Virtual_console

When you hit ctrl-alt-F1 you switch to the first virtual console. Hit ctrl-alt-F2 you switch to the second and so on and so forth for all the different F keys.

Each virtual console then runs a console output. It can be X Windows, standalone GL graphics, VGA text console, FBdev text console, and other such things.

Typically you have 1 X windows console and then 6 or 7 text consoles configured by default. The text consoles are controlled by a program called a 'getty' and the X11 console is controlled by your X Windows Server.

like this:
root@machinename:~# ps -ef|grep getty
root 3885 1 0 03:08 tty1 00:00:00 /sbin/getty 38400 tty1
root 3886 1 0 03:08 tty2 00:00:00 /sbin/getty 38400 tty2
root 3887 1 0 03:08 tty3 00:00:00 /sbin/getty 38400 tty3
root 3888 1 0 03:08 tty4 00:00:00 /sbin/getty 38400 tty4
root 3889 1 0 03:08 tty5 00:00:00 /sbin/getty 38400 tty5
root 3890 1 0 03:08 tty6 00:00:00 /sbin/getty 38400 tty6
root 10541 4589 0 06:32 pts/0 00:00:00 grep getty


TTY is just the traditional name for text console. It's a throw back to the ancient days when all we had were serial consoles to big machines.

http://en.wikipedia.org/wiki/Teleprinter

http://en.wikipedia.org/wiki/VT100

Traditionally you had F1-F7 virtual consoles controlled by a getty and then F8 was your login for X Windows. However Fedora systems and a couple others have moved to having F1 being X. But you can configure them to be anything you want, really. A lot of time Linux installers, for example, will have the installer run on F1, have a root shell on F2 and F3, and have various logging information showing on F4 and F5.

Right now if you want real multi user sessions in Linux you have to depend on hacks with X windows or you have to switch back and forth using ctrl+alt+F* and have the Linux kernel control it.

They want to move away from that because it causes usability and/or performance issues. They want to have the ability for more flexible multiuser configuration setup.

In short, we admit OS X has is right.