Croad Langshan's questions

There are several pages describing how to build Ubuntu live CD images. Where is the code used to build the official live CD images?

To be more precise: I'm talking about the particular code (maybe it's a single script, I don't know) used by Canonical to build the official images, not the source code for the generic tools (like squashfs) that are used by that code.

I'm assuming here that such code exists, and is published! Maybe somebody at Canonical sits down and does it by hand every time.

Note that I'm not looking for an alternative way to build live CD images here: rather, I want to look at the code that was used to build the official images.

I can make a live CD image from the original 16.04 ISO image following these instructions:

https://help.ubuntu.com/community/LiveCDCustomization

My "remastered" ISO boots fine using kvm.

When I use the original 16.04 source ISO in "startup disk creator", I get a bootable USB, of course.

However, when I use my remastered ISO with "startup disk creator", it does not result in a bootable USB (at least with the PC I'm trying to boot it with). I notice that the USB I get from my remastered ISO shows up as only (say) /dev/sdb, but a USB from the original ISO (same USB stick) shows up as: /dev/sdb, /dev/sdb1, /dev/sdb2

So, I'm guessing maybe this has something to do with UEFI. But how can I make a USB stick created from my remastered image bootable?

I'm trying to support a naive user remotely (using teamviewer). She has a problem where update-manager is not automatically starting (had not shown an software updates window for weeks until today). Checking the "Software & Updates" settings, everything looks fine (check for updates daily, display immediately when there are security updates).

So, how is update-manager supposed to be automatically started? (if I know this I can try to debug) For example, to illustrate the kind of answer I'm hoping for:

• aptd? Via what configuration, triggered how?
• Some init.d script? Which one?
• upstart? Which job file?
• systemd? Which unit file?
• cron? Which crontab?

Bonus points for clues re why it might be failing!

I see that the GUI configuration for update-manager has a maximum check interval of once per day. I'm sure Canonical thought about this carefully, but these days I don't want to be without a potentially important update for as long as 24 hours.

How can I set up my desktop system so that it:

• Automatically applies security updates
• Checks for security updates more frequently than once per day (if this can be done via push notifications rather than checking regularly, perhaps better)
• Promptly graphically prompts for reboot if necessary (for bonus points: UI should explain why the reboot is needed, e.g. reference to updated package changelogs / CVEs)

Should I use unattended-upgrades, or run update-manager from a crontab, or something else? How can I configure these tools to achieve what I want?

I'm considering getting a Nexus 7 to do some multi-touch development on Ubuntu in the run-up to 13.04 (i.e., now :-).

What APIs, /dev files, or protocols are available, or could be made available with not too much work on my part? What data is available from the device?

The data I want to get my hands on is -- if I can -- the same as I get from /dev/uinput/event* from an Apple Magic Trackpad, viz:

1. positions of all touches (could be as many as 10 simultaneous touches, but much more typically 6 or fewer)
2. their size/pressure (in both x and y directions)
3. their angle
4. their identity -- i.e. an integer that is somewhat reliably preserved across touch events, for as long as a finger doesn't lift off the surface

Not all of this data is essential -- but the more of it there is, the merrier.

What program starts the per user session dbus-daemon process in GNOME 2 and GNOME 3 (presumably via dbus-launch)? I would like to know because I would like to add a directory to the list of directories that dbus-daemon checks for .service files.

(Obviously if it's a sh program, "sh" isn't the answer I'm looking for ;-)

How could I have answered this question for myself efficiently? What documentation is there on desktop and session startup?

Blu-ray writers have reduced in price a lot recently, but there are few success stories on the web about writing blu-ray disks using Ubuntu (and the same goes for GNU/Linux in general).

Are any of the new low-cost blu-ray writers supported? Can anybody confirm that they've personally used them with success? What software did you use (I'm most interested in tools that operate at the hardware/protocol level, such as growisofs, rather than the GUI tools that wrap them)?