XOrg Linux layout setxkbmap us,ru -option grp:caps_toggle

$ cat /etc/X11/xorg.conf.d/12-keyboard-layout.conf
Section "InputClass"
Identifier "Keyboard Defaults"
MatchIsKeyboard "yes"
Option "XkbLayout" "us,ru"
Option "XkbOptions" "grp:caps_toggle,compose:paus"
#grp_led:scroll,compose:lwin"
EndSection

для *ubuntu:
/etc/default/keyboard
/etc/default/console-setup
/usr/share/X11/xorg.conf.d/12-keyboard-layout.conf