Monthly, I run a cron job that `apt-get updates/upgrades` my Ubuntu 15.10 Desktop system, then reboots. Consistently, the reboot hangs forever with the console screen showing the Ubuntu boot screen with the flashing colored dots. I have to cycle the power and then it comes up fine. I do have grub installed -- not sure if that matters.

Any idea what's going on?

It takes some time to install the updates after download them.

I think it is not a good idea to run a cron job.

A background service is running to check, if updates are availaible.

Just install them manually.

Yes, that's one reason I'm doing it in a cron. The idea is to periodically, automatically update all workstations in an office. Al la Windows Update.

Why?

Notice of available updates is only given if the logged-in user is a sudoer. Normal workstations users do not have this permission. It is impractical for the office sysadmin to log onto each workstation and manually update.

I've seen this issue about Ubuntu booting and hanging at the splash screen in quite a few posts elsewhere on the web, not related to software updates. Is this a general issue with Ubuntu? (anyone?)

Unrelated: I've asked this question and several others on askubuntu.com over the past 6 months, some of which have hundreds of views, but all of which have zero answers. I get most of my ubuntu help right here on LQ. Is Ask ubuntu a dead list?

Updates are usually no problem with ubuntu, however upgrades can be.
I have had a variety of bugs, glitches, frozen screens, following upgrades.
The result being that I do update ubuntu but never upgrade, instead I do a new install
when I want the new version. This can be time consuming if you are using a lot of
additional programs and software.
From what I've read, Mint seems to have better success with the upgrades, since 17.0.
Edit;Regarding the upgrades, there is another perspective in this thread,
see post nu.12.
https://forums.linuxmint.com/viewtop...86269#p1186269

from the apt-get man page:

update is used to resynchronize the package index files from their sources.

upgrade is used to install the newest versions of all packages currently installed on the system ...

dist-upgrade in addition to performing the function of upgrade, also intelligently handles changing dependencies with new versions of packages.

I assume (hopefully) that you mean "dist-upgrade" in your comment. The "update" does no more than update the package list. The "upgrade" function actually updates the packages -- and a reboot is generally needed afterward to run the newer stuff.

I don't think you install from scratch to just get the "updates" so described, do you?

But, that is another question I was going to post if I didn't find an answer somewhere: Can I Upgrade my Distro version, e.g. from 15.10 to 16.04, without having to install 16.04 from scratch? I really hope so as I have lots of additional software and customizations I'd hate to do all over for every workstation. That's old-school Microsoft! Nowadays you can even Upgrade from WIN7 to WIN10 without losing everything.

Yes you are correct about the upgrade, I use the term upgrade to mean system upgrade.
You can upgrade from 15.10 to 16.04, although I haven't done it myself.
http://www.ostechnix.com/upgrade-ubu...buntu-15-10-2/
The Windows upgrades worked well for me, upgrading to Windows 10.

It could be related to the Ubuntu computer being a laptop. I've had troubles with this in other cases, specifically, using apcups. When there is a power failure the Ubuntu laptop (a different one) either does not completely shut down, or, when power is restored, doesn't come up -- it's one or the other, I can't recall which. In any case, the "dots" splash screen stays up forever until the laptop is powered off and on -- just like this case with the update/reboot. I've not tried this on a desktop yet as I don't have any configured with Ubuntu.

Just a question, maybe not relevant, does this mean that you are running the laptop on electrical grid power
constantly? As opposed to using the battery?

Well, it *is* a laptop, so whether it's plugged on or not, I suppose it's running on battery, no? But, to answer your question directly, the laptop I'm having the update/reboot issue with is plugged in always.

(Note: the apcups issue was a different laptop, I only cited that because it also hung with the dots-splash-screen forever on restart)

I don't know about your issue however Cron seems a fine idea to me. Why update only once a month, not like it's LTS?
https://wiki.ubuntu.com/WilyWerewolf...s#Known_issues
https://en.wikipedia.org/wiki/Ubuntu...ly_Werewolf.29

Interesting links, esp. the first one. thanks. I may pursue a bug report if I can confirm this problem occurs on other than just my laptop.

To answer your question, "Why update only once a month?" Well, for one thing, I don't want to have to cycle the power weekly or daily! I mainly access this computer remotely via VNC. This problem means a trip to the office to cycle the power every time I update.

I found the links trying to see about Ubuntu's LTS verse experimental or cutting-edge, where security flaws could potentially pop up daily? I'm still unsure on it but would think your okay just number wise: http://www.ubuntu.com/info/release-end-of-life
maybe worth more digging if security is a big issue?

Based on the information at the Ubuntu site below, you might take a serious look at upgrading your 15.10.

https://lists.ubuntu.com/archives/ub...ly/000208.html

The apcupsd problem I has was with 14.04 LTS. Yes, I've already burned the 16.04 DVD, just haven't had a chance to try it yet. I'm doing some research to see if I can upgrade without a wipe/install -- I have quite a few system configs I don't want to lose.