Kubuntu 15.10 unbootable after failed updates

[theodorn]

Hello everyone,

I installed Kubuntu 15.10 on a USB stick, with YUMI-multiboot. After I tried to update, I got a notification that I was out of memory. After a few minutes of no apparent progress, I got a message that the updates failed and my configuration might be broken. Which it turned out to be, I forced a reboot with the reset button on my computer, and the computer booted into a blank screen, only with the default background picture. The mouse cursor was visible, and I could move the mouse, but that was it. No GUI, besides that.

So I have a few questions, which hopefully somebody can answer.

1. Doesn't Kubuntu save a last known good configuration and revert to it, in case of failed updates?
2. Another question is - how much memory does this thing need to gobble up? I gave it 2GB of persistence in YUMI, thought it would be enough, as so many are saying Linux is so light on resources. The system had about 1.2 GiB free at the beginning, but after I ran the updates and Firefox, it quickly reduced to about 200 MiB, then to zero. That was when the freeze came about, not surprisingly maybe, as the system had run out of memory to work in.
3. Besides, the system log monitor showed that Kubuntu didn't touch my RAM, of which I have 8GB. Isn't the OS configured to utilize RAM, even when running in USB live mode?
4. Or is this a failure of YUMI-multiboot?
5. Does anyone know if it's possible to configure a live Linux, installed by YUMI, to use RAM?

I had planned to use these 2 GB of persistence mostly to install updates and my own files. The USB flash drive I'm using is 16GB, but I intend to install a few more Linux distros on it, for testing purposes mostly. I really like the KDE desktop, but these beginning obstacles are quite disheartening. Besides, the environment feels slow and unresponsive. I know that a USB live install is not as fast as from the hard disk, but other distros, like Linux Mint Cinnamon and Xubuntu 15.10 XFCE, are fast and responsive, under the same circumstances (a live USB install.)

[claydoh]

I don't know anything about yummiboot, but persistence is not ram, but is hard drive space. Update downloads and new programs take up that space, as well as whatever data you have created and saved - email, wallpapers, documents, extra widgets and the like. The OS is still using your system's physical ram.

Fixing this should be easy. You'll need to get to a terminal - ctrl-alt-f1 will get you to a vt.
Then you need to finish the package installation that did not finish:
sudo dpkg --configure -a
Then you should check than there were any packages that didn't install at all
sudo apt-get -f install
It does not hurt to do these two steps more than once.


Yes, linux can be low on resource usage, but desktops like Gnome, Unity, and Plasma are not so low, let alone modern web browsers. Then add in the fact that the live isos you are running are actually compressed images that have to be unzipped and loaded into ram on the fly. A normal OS that is not compressed and is physically installed to disk takes anywhere from 6 to 8 gigs that has (more or less) comes from that compressed 1.5 gig iso image you are running on your usb stick.


Now, as you are running the OS from a live image, which means that actual changes/updates to the system are stored on the persistence portion, I do wonder if it would be as simple as removing certain files and directories from that would revert things back to stock? I do not know.

[theodorn]

Thank you, claydoh, for this useful information. I have already uninstalled Kubuntu from my USB, and I'm right now in the process of reinstalling it, to try once more. It's easy to do in YUMI. I gave it 3 GB of persistence, let's see if it works! Linux Mint Cinnamon 17.3 hardly went under 1 GB left of disk space (with 2 GB persistence as well) but I've read - and experienced - that KDE is heavier on resources. If it won't work, I'll possibly just install Kubuntu as the third OS. I'm already dual-booting with Windows 10 and Ubuntu Studio 15.10.

Regarding moving files and directories, I hardly had any user files, and I'm a bit reluctant to delete files created by the operating system and possibly needed to run it. I had installed Kdenlive, but apart from that, no changes had been made, prior to the first system update.

[claydoh]

Your Kde is getting a bigger number of updates, as well possibly more kernel updates , than Mint and cinnamon,and thus using more disk space from the new packages downloaded . You probably can save a lot of drive space on your flash drive by purging the package cache more regularly. You can do this from Muon Package Manager (if it is installed), which has an option in it's settings to how often this is done, or via the command line via sudo apt-get clean.

[theodorn]

I ran sudo apt-get clean and autoremove, after the updates. Now with Firefox, Dolphin, and Kdenlive open, disk space stays at 1.1 GiB. I turned off desktop effects, and everything seems to be running smoothly. Thanks for the help.

[Teunis]

During an upgrade the temporary files are stored in / (root) and according to my experience you need it to be at least 12-14GB in size to not run into problems.
The space used for persistence is subtracted from the total space of your drive.
On such such small drives you're better of not using a separate /home and /boot partition.
Of course it also depends on the number of applications your run.

B.t.w, it's a nasty and patently wrong rumour that KDE/Kubuntu is heavier than other desktop environments.

[theodorn]

Teunis, are you saying that only the /boot directory (or file, if in Linux, no distinction is made between files and directories) needs to be 12-14 GBs, or the whole root (/) partition?

The problem also is, that I can't see the remaining space of my 16 GB USB (reported as 14,48 GiB, the binary figure), when running Kubuntu in live USB trial mode. KDE Partition Manager says it's one partition, /dev/sdb1 with the label MULTIBOOT. In Dolphin, three drives turn up, MULTIBOOT, and two instances, each named Loop Device. It seems Yumi won't let me access or utilize the remaining space. I wonder if Kubuntu can make use of it. I also have Linux Mint on the USB. It probably doesn't matter though, as I'm contemplating on installing Kubuntu 15.10 to my hard drive.

About KDE being heavier on resources, yes it is not a problem any longer. As I said it runs fine now, after I gave it a bit more space. I'm not that much for fancy rolling around of windows when they're moved or closed, but the overall look of the desktop is very pleasing. Good work the Kubuntu team has done on the KDE.

I have some questions about hard disk install, but I'll ask in the Pre-installation forum, since it involves partitions.

[Teunis]

My excuses, I made an error talking about /boot, I meant a separate / (or root)

Sounds like you have not made partitions like /, /swap and /home and this will lump any and all the free space into the same which on such a small drive is probably best.
My experience is that a / partition of less than ~12-14GB will cause a full disk during a distribution upgrade when the whole new distro is loaded in /temp. (a sub directory of /)

I also have Linux on a few USB drives, one of them is like yours 16GB and it works.

[theodorn]

I get it now, thanks for the explanations.