Re: udev questions

[Timo Juhani Lindfors <timo.lindfors@iki.fi>]

Paul Thomas <pthomas8589@gmail.com> writes:
> I'm using emdebian grip lenny. Currently mounting the / over nfs. I've

I'm using normal lenny so what I say here may or may not apply to
emdebian.

> I don't see any /dev or udev entry in /etc/fstab. How does the system
> know where and how to create "udev on /dev type tmpfs (rw,mode=0755)"?

/etc/init.d/udev mounts it:

  # mount a tmpfs over /dev, if somebody did not already do it
  ...
  if ! mount -n -o size=$tmpfs_size,mode=0755 -t tmpfs tmpfs /dev; then
  mkdir -p $udev_root/.udev/db/

> Where does /dev/.udev/db come from? It's not on the nfs shared

My guess is that udev generates it. The udev_device_update_db()
function in libudev-device-private.c does things like

if (udev_device_get_devlink_priority(udev_device) != 0)
        fprintf(f, "L:%u\n", udev_device_get_devlink_priority(udev_device));
if (udev_device_get_event_timeout(udev_device) >= 0)
        fprintf(f, "T:%u\n", udev_device_get_event_timeout(udev_device));
if (udev_device_get_num_fake_partitions(udev_device) != 0)
        fprintf(f, "A:%u\n", udev_device_get_num_fake_partitions(udev_device));

and the lines in the files in /dev/.udev/db have exactly this format.