Ubuntu upgrade 12.10->13.04: fails to reboot at the end

[Teo]

I've upgraded from 12.10 to 13.04.
At the end of the process (after getting packages, installing packages, cleanup), the computer was supposed to be restarted: I chose Ok.
After the screen turned off (note: it's not just that the screen went black, it had turned off: you can tell the difference because a turned on black screen still sheds some light), the fan kept spinning at medium-high speed (but no disk activity apparently occurred) forever, meaning several minutes, but the reboot never got finished. Until I forced a power off and power on.

[Ubuntu Foundations Team Bug Bot (crichton)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. It seems that your bug report is not filed about a specific source package though, rather it is just filed against Ubuntu in general. It is important that bug reports be filed about source packages so that people interested in the package can find the bugs about it. You can find some hints about determining what package your bug might be about at https://wiki.ubuntu.com/Bugs/FindRightPackage. You might also ask for help in the #ubuntu-bugs irc channel on Freenode.

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[Teo (teo1978)]

This is not just the one reboot just after the upgrade: it's almost every shutdown since I have upgraded.

That is, shutdown ALMOST SYSTEMATICALLY fails. It definitely fails more than 50% of the times. It only succeeds from time to time.

The symptoms are always the same:
After the laptop's screen has already been turned off (not just gone black: turned off), cpu consumption goes a bit higher (I can tell because of the speed of the fan) but there is no disk activity, and the computer never turns off (or restarts in the case of a restart).

This is a huge REGRESSION with respect to 12.10, where shutdown used to fail pretty often but not even closely this much; also, I'm not 100% sure but I think it used to hang before the screen got turned off.

[Paul White (paulw2u)]

Thank you for reporting this bug to Ubuntu. Both releases have now reached End of Life (EOL)
See this document for currently supported Ubuntu releases: https://wiki.ubuntu.com/Releases

If you're still seeing this problem with future upgrades please increase the verbosity of the steps to recreate it so we can try again.

[Launchpad Janitor (janitor)]

[Expired for Ubuntu because there has been no activity for 60 days.]