ConsoleKit

Warning: From ConsoleKit's web site:
ConsoleKit is not actively maintained. The focus has shifted to the built-in seat/user/session management of systemd called systemd-loginctl.

See the 2012-10-30 news announcement: https://www.archlinux.org/news/consolekit-replaced-by-logind/

If you are looking for a convenient way to mount disks as user, have a look at udev, udiskie and PolicyKit. For Arch support, you need to switch to systemd.

Arch Repositories

ConsoleKit is no longer packaged in the official repositories [1]. It is strongly discouraged to continue to use or to start using ConsoleKit.

Replacing ConsoleKit with systemd-logind

Note: Starting with polkit 0.107-4, ConsoleKit must be completely replaced by systemd-logind[2], even when using a display manager. The system must be booted with systemd to be fully functional.

An easy method to be able to remove ConsoleKit is to automatically log in to a virtual console and start X from there. It is important that, as mentioned in the latter article, the X server is started on the same virtual console that you log in to, otherwise logind can not keep track of the user session. You can then simply remove ck-launch-session from your ~/.xinitrc.

In order to check the status of your user session, you can use loginctl. To see if your user session is properly set up, check if the following command contains Active=yes. All PolicyKit actions like suspending the system or mounting external drives with Udisks should then work automatically.

$ loginctl show-session $XDG_SESSION_ID