Udev rules to own a dm disk

Just making this big mental/virtual note of how to assign LVM volumes’ ownership: a /etc/udev/rules.d/99-my-volume.rules with the following contents:

SUBSYSTEM=="block",KERNEL=="dm-*",ACTION=="add|change",ENV{DM_NAME}="my-devicemapper-volume-name",OWNER="myusername",GROUP="myusergroup"

Also, this trigger comes handy to test the changes:

sudo lvchange -an my-volume-group/my-volume
sudo lvchange -ay my-volume-group/my-volume

Logging gnome-screensaver’s debug output during normal startup

jani@saegusa:~$ cat > gs-debug.sh
#!/bin/sh
gnome-screensaver --debug 2>~/gs-debug.log
jani@saegusa:~$ chmod +x gs-debug.sh 
jani@saegusa:~$ sed 's@^Exec=gnome-screensaver$@Exec=/home/jani/gs-debug.sh@' /etc/xdg/autostart/gnome-screensaver.desktop > ~/.config/autostart/gnome-screensaver.desktop