changes to udev system...

[stychokiller]

I'm lost on writing udev rules for Kubuntu 12.10!
The changes to where files are located (now apparently in /lib/udev/rules.d),
why some USB devices mount with no problem, others NEVER get found, etc.

Is there some comprehensive documentation on the udev system?

For example, when an audion CDROM gets loaded, /dev/cdrom does not get created,
yet the notification system does ask me to select an app to apply for the audio CD.

I'd be happy to solve this particular udev problem.

I have written the udev rules.d file that allows my PC to use my Hp webcam,
so I'm not completely helpless. All the help I've been able to find on the intrawebz
is usually out of date.

[kubicle]

The changes to where files are located (now apparently in /lib/udev/rules.d)

Custom local rules should still go to /etc/udev/rules.d

I may have misunderstood your problem, but audio CDs aren't mounted (they generally do not have a standards compliant filesystem that could be mounted)...they can still be played with a music player or "browsed" with the audiocd:/ kio-slave, for example (this is what is used if you decide to "Open an audio CD with the file manager"....the audiocd:/ kio slave can also be used to "rip" tracks in your chosen file format (audiocd kio slave is in package 'audiocd-kio' if it's not installed on your system).

[stychokiller]

Some programs expect to find /dev/cdrom or /dev/dvd when a disk gets inserted into the drive,
but the only device remains /dev/sr0. A temporary directory does get created in /media for the
cdrom however. Like most of linux, udev now has way too many moving parts. It's not like a
programming language, where "if" means one thing and "while" quite another. Somewhere,
someone or some group knows how the udev system works, I'm just asking them to supply a link
to the documentation, their wetware is not readable by me.

[kubicle]

Would this do? (this should create /dev/cdrom, /dev/cdrw and /dev/dvd symlinks targetting /dev/sr0):

/etc/udev/rules.d/75-my-cdrom-symlinks.rules

# Set symlinks for sr0
KERNEL=="sr0",        SYMLINK+="cdrom"
KERNEL=="sr0",        SYMLINK+="cdrw"
KERNEL=="sr0",        SYMLINK+="dvd"

(that's somewhat "quick and dirty", but should do the trick (again, if I understood your problem correctly)

As far as documentation goes, I'd start with 'man udev' and 'man udevadm'
http://wiki.debian.org/udev might also be useful.

[stychokiller]

changes to udev system... [SOLVED]

After a quick

udevadm trigger

the missing /dev/cdrom, etc.
appeared! Thanks (now, on to installing gentoo Linux on a different hard disk, cause
Kubuntu is almost useless for compiling source-code packages from non-Kubuntu
sources -- why not add a working /usr/src/linux environment? Kubuntu is hopelessly
bloated, so a bit more wouldn't be noticeable!)

Mark this problem as [SOLVED] (but I'm still looking for more info on the udev system...)

Would this do? (this should create /dev/cdrom, /dev/cdrw and /dev/dvd symlinks targetting /dev/sr0):

/etc/udev/rules.d/75-my-cdrom-symlinks.rules

# Set symlinks for sr0
KERNEL=="sr0",        SYMLINK+="cdrom"
KERNEL=="sr0",        SYMLINK+="cdrw"
KERNEL=="sr0",        SYMLINK+="dvd"

(that's somewhat "quick and dirty", but should do the trick (again, if I understood your problem correctly)

As far as documentation goes, I'd start with 'man udev' and 'man udevadm'
http://wiki.debian.org/udev might also be useful.