On Mon, 12.08.13 01:44, Tony Seo (tonys...@gmail.com) wrote: > I sincerely ask you a relationship between device unit and boot time if I > remove unnecessary device unit. > > And also, can I ask you detail process of making device unit by systemd? > (I alread read the manual page related with device unit)
the kernel creates a directory in /sys for each device popping up. udev then maintains some additional metadata for all those devices. One part of that metadata is a "tag" that might be on select devices called "systemd". If a a device is tagged like that it will also show up as .device unit systemd. By default block devices, ttys and a few others are tagged like that. Some services need to wait for some block devices before they can be run (for example, fsck instances need to wait for their respective block devices to show up before they can be started), and this is implemented via dependencies to these device units. Device units hence are not really something active in themselves, they just reflect as units state of another component of the OS (which is udev/kernel). Lennart -- Lennart Poettering - Red Hat, Inc. _______________________________________________ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel
