Postings by Volker Wysk

Re: wiped disk - no longer bootable

Zitat von Volker Wysk <>:

It's crazy.

wiped disk - no longer bootable


The problems pile up. I've wiped the first megabyte of both devices
(HDD and SSD), because I got a message on boot which sayed that the
disk with a specific ID can't be found. Using "dd if=/dev/zero
of=/dev/sda ...". Then installed Ubuntu again, which appeared to
succeed. But when booting now, it says that there is no bootable medium.

So I have wiped something which I shouldn't. How do I restore that? It
doesn't seem to be something which fdisk does.



Fwd: Filesystem corruption - Problem strikes again


The !$"% problem shows again. I can't boot any longer. The password is
rejected. When started in recovery mode, it says that the volume group
"ubuntu-vg" is not found, and that /dev/sdb2 can't be unlocked because
it is not a valid LUKS device. /dev/sdb2 is the (encrypted) part of
the SSD, in which the cache for the HDD is stored.

I'd send a photo, but the mailing list rules don't allow that.

So the problem occurs very early, when unlocking the crypto discs. Not
sure what that tells us.

Any ideas??


Filesystem corruption


I've brought my machine to the computer shop. They checked everything,
especially the PSU and the main board. All the capacitors are okay.
They couldn't find anything.

The main board is quite old, must be more than ten years. The HDD is 3
1/2 years old.

Now I still don't know the reason of the data corruption, which
wrecked my Kubuntu system. I've installed a new Ubuntu-19.04, and
found no corruption so far. The problem can't be reproduced.

Filesystem corruption - hard disk exploded!


That filesystem corruption of mine has quickly expanded. It has expanded to
the boot partition and the LVM metadata, last.

I've booted into memtest86+, but have aborted after an hour, in order to let
it run overnight. But then I couldn't boot the machine any longer. Going into
rescue mode revealed that the cryptsetup binary (same as before) looks
corrupt. Also, the volume group wasn't found.

Before that, I've tried to log in to KDE. This failed with a message, that
some KDE file can't be executed.

Garbage in package info (Help!!)


Something went seriously wrong with my installation.

I can't run cryptsetup:

desktop ~ % LANG=C cryptsetup
/sbin/cryptsetup: line 2: syntax error near unexpected token
331|\366\302*? (...)

I've tried to reinstall it, but this leads to this:

desktop ~ % LANG=C apt-get install --reinstall cryptsetup
Reading package lists... Done
Building dependency tree
Reading state information...

Kubuntu 18.04.2 LTS -> Ubuntu 19.04


I'm about to say KDE goodbye, and switch to Gnome3.

Which is upgraded every half-year as part of Ubuntu. I don't think
there exist PPA's for Gnome, in the same way as for KDE, that give you
the newest Gnome. So I have to drop LTS and "swim with the crowd",
getting a new Gnome version every half-year, as part of Ubuntu.

This means that I have to migrate from my 18.04.2 LTS system to the
newest Ubuntu version.

Can this be done with do-release-upgrade or something like that? I
really don't want to set up everything from scratch _again_. There's a
lot to setup.


Kernel problem with scanner


My Canon CanoScan LiDE 220 scanner had worked reasonably well, until a
new kernel has been installed. It went into stop-and-go mode, and made
funny noises. This is worse in higher resolutions.

I had a notion that it might be a problem with USB, which in turn
resides in the kernel. I was right. The most current kernel, which has
been installed, was version 4.15.0-50. The previous one (which still
is available) was version 4.15.0-48. I tried that version, and the
problem went away.

Will this message be read and the problem fixed?


Backup and upgrade of running programs


There's something that has troubled me for a long time. When you make a
backup, or do an upgrade, what happens when the affected programs or data are
still running or in use? Wouldn't this mean trouble?

There are a lot of programs for doing a backup or an upgrade, which let the
user do just that. For instance, KDE Discover and the KDE Muon Package
Manager. I'm not using those much, because I prefer command line. But it seems
like they let you upgrade a (running) program by doing nothing more than a few

apt-file does not work for specific package


I've installed the nextcloud desktop client with a third-party PPA:

% cat /etc/apt/sources.list.d/nextcloud-devs-ubuntu-client.list
deb <a href="" title=""></a> bionic main

% apt update
OK:7 <a href="" title=""></a> bionic InRelease

The package is nextcloud-client:

% dpkg -L nextcloud-client

But apt-file won't find any files in it:

% apt-file list nextcloud-client
(no output)

"apt-file search nextcloud" doesn't work either.

But apt-file does work with other pack

KMail: "Could not create collection trash, resourceId: 2"


I'm getting a bad error from KMail:

"Im E-Mail-Programm ist ein schwerwiegender Fehler aufgetreten. Das Programm
wird beendet. Die Fehlermeldung lautet: Could not create collection trash,
resourceId: 2"

(Translation: "In the email program, a grave error occured. The program is now
being terminated.

Release-upgrade broke internet connection


The hint, that /etc/resolv.conf should probably point to
/run/systemd/resolve/resolv.conf was correct. The connection is back.

Now, my desktop (after being online again) sucks all the mail from my
mail provider, and places it in my local IMAP server (Dovecot). Which
doesn't work yet. There are problems with kmail. So, at the moment, I
don't have a working email connection any more. (Last, I've used a
webmail interface).

I have to repair my mail connection, before I can answer any mail.

Bye, and thanks for that hint!


release upgrade breaks internet and other things


I've done a do-release-upgrade on my 16.04 LTS system. This has broken
the internet connection, and more. I get immediate "unknown host"
errors when I ping to any host. When I lookup an adress in Firefox, I
get a "Page not found, The connection to the server ... failed."

Sorry, I don't know how to troubleshoot this connection problem.

Where should I look..?

Should i even look, or would it be easier to reinstall everything in a
new 18.04.1 system from scratch? (This would be quite a few things.)


How to recover using a full backup?


I'm making full backups of my system, on an external hard disc. It's a
combination of incremental and differential backup (accoding to the definitions
on wikipedia). So there isn't included everything in each backup, but only the
difference to the last time (or one of the last times, to be correct). This
works well.

The backup contains almost everything, excluding only things like /tmp,
/home/.../tmp, /dev, /proc and a few others.

I've needed to resort to parts of the backup in various occasions, but I never
needed to restore the full system.

Kworkers, Kworkers


Again, those pesky kworker threads are taking over my machine. Right now, I'm having 45 of those. The hard disk is working all the time, but this doesn't slow down the system. Probably because I also have an SSD.

Does anyone know, what this is about? Is it a known (kernel) bug? Should I worry? How to get rid of those things ...?


Lots of kworkers


Every few days, I get a lot of kworkers (some 50) in the process list. The hard disk clatters all the time. From the web I've found that those are kernel threads. Since I have an SSD (apart from the harddisk, set up as a cache for the HD), this doesn't make my system unresponsive. But still...

What's going on here? And how to get rid of all those kworkers?


(solved) KDE root programs' fonts very small


I've had the problem, that graphical programs (or program parts), which run as root, had a very small font size - such as systemsettings5 or muon's settings->configure software sources window.

I've investigated it, and I found that the following has to be added to /etc/environment:


That is, the XDG_CURRENT_DESKTOP environment variable needs to be set to "KDE". But this doesn't work when set in ~/.bashrc, ~/.proile or /etc/profile. Looks like these scripts aren't called by kdesudo.

Tiny font in Synaptic


I'm running a Kubuntu 16.04.3 LTS system. Reading the mailing list kubuntu-users (and ubuntu-users), made me want to try Synaptic. But the font is so small, you can hardly read it.

Is there a straightforward way to make the font bigger?


Comprehension question with sftp connection in konqueror


I've had ssh installed, and configured it to allow authentification with public keys only. Password authentification is turned off. I've set the SSH port to 3322.

It all worked fine (including sftp in konqueror). It still does, with the exception of sftp in konqueror. I can access my laptop from my desktop machine via ssh, scp and sftp, and vice versa.

Kontact bug (?): Can't synchronize with CardDAV ressource


I've edited a contact in the addressbook, but I can't get the changes synchronized with my Nextcloud server (via CardDAV).

When I click on "Update addressbook folder" in the menu in the "Contacts" section of Kontact, then I get this message:

Before syncing folder "Kontakte" it is necessary to have the resource online. Do you want to make it online?

I click on Yes, but then the dialog closes and nothing happens. Next time, the same question comes again. The changes don't make it to the CardDAV server, what can be seen in its web interface.

Any ideas?


Brieftasche kaputt


Ich weiß nicht, was passiert ist, doch plötzlich ist der KWallet-Dienst nicht
mehr verfügbar. Wenn ich mich in Plasma einloggen, bekomme ich Fenster, die
Paßwörter abfragen. Und zwar eins für KMail und eins für den

Kwallet broken


I don't know, what has happened, but suddenly Kwallet is no longer available.
When I log in to plasma on my desktop, I get two windows, each asking me to
enter a password - one for KMail and one for the Nextcloud-desktop-client.
(I'm writing this on my laptop.)

There is this error message: "Couldn't open wallet:
org.freedesktop.DBus.Error.NoReply; Message recipient disconnected
disconnected from message bus without replying"

When I open the KWalletManager, the wallet is empty.

What happened, and how to fix this?


Kwallet broken


I don't know, what has happened, but suddenly Kwallet is no longer available.
When I log in to plasma on my desktop, I get two windows, each asking me to
enter a password - one for KMail and one for the Nextcloud-desktop-client.
(I'm writing this on my laptop.)

There is this error message: "Couldn't open wallet:
org.freedesktop.DBus.Error.NoReply; Message recipient disconnected
disconnected from message bus without replying"

When I open the KWalletManager, the wallet is empty.

What happened, and how to fix this?


Grub error: "will not proceed with blocklists."


I'm afraid I have broken something. grub-install outputs this message:

desktop ~ % LANG=C grub-install /dev/sda
Installing for i386-pc platform.
grub-install: warning: this GPT partition label contains no BIOS Boot Partition; embedding won't be possible.
grub-install: warning: Embedding is not possible. GRUB can only be installed in this setup by using blocklists.

How to recover with a full backup?


I'm making preparations for the case when I can no longer boot my machine, and I'm not able to recover with the GRUB recovery mode.

I have a full backup, which includes the system as well as personal data.

When I can't recover, I would install the system anew, from the Kubuntu installation ISO. Then I would unpack my backup, in some directory /backup. Now, how to get a running system again, from that? Could I just replace the top level directories with ones from the backup? Such as:

cd /
mv /bin bin.tmp
bin.tmp/mv backup/bin bin
rm -r bin.tmp

Now, how to make it bootable?

LVM: How to access a foreign volume group


I'm about to set up an LVM cache (for my encrypted root file system). This involves attaching a cache pool LV to the origin LV to be cached, as the last step:

lvconvert --type cache --cachepool kubuntu-vg/cachedatalv kubuntu-vg/root

I've got it working in a virtual machine, but I'm hesitant to apply the procedure to my production system. It would be bad, if I had to restore it from a backup, because I have installed and configured a lot of things.

So, in case something goes wrong, I want to be able to start a rescue system and undo the attaching of the cache pool LV to the origin LV.

Kubuntu-PPAs for Artful


I've done a "do-release-upgrade" from 17.04 to 17.10, and I got the message
"Paketquellen von Drittanbietern deaktiviert" ("package sources for thrid
party providers deactivated").

It turns out, that it has rewritten my Kubuntu PPAs in /etc/apt/
sources.list.d/ from "zesty" to "artful", and at the same time commented out
these lines:

# deb <a href="" title=""></a> artful main


# deb <a href="" title=""></a> artful main

How do I configure the new Kubuntu PPAs, for Artful?

(Solved) It's All Text vs. Textern in Firefox 57


I'm writing this message for folks, which encounter the same problem with Firefox 57, that I did.

You heard of it: There is a big retrofit to Firefox in Version 57. This means that many addons don't work any longer and need to be ported to the new firefox version. (Addons now need to use the WebExtensions API).

There's the It's All Text addon, which I've used up to firefox version 56. It has been used to launch an external text editor for editing text areas. It doesn't work with Firefox 57.

(Solved) Internet is dying


I've connected my desktop to the router with the new cable, for some
17 hours now. (Had to squeeze the cable....) The laptop isn't involved
now, and there habe been no occurrences in the output of ping at all.

I don't know, what had been wrong. Is it the cable? The cable only?
It seemed like the router was broken.

I'll leave it at that, although there are unanswered questions, and

Thank you, to Xen and Colin Law, amongst others, who helped me.


Internet is dying - or is it..?


I'ts stupid. When you want things to work, they're broken. When you want them
to be broken, they work! Well, mostly.

I've purchased a new network cable, and am running ping on both of my machines
(desktop and laptop), for some 14 hours now. Both are connected by cable, with
the desktop (with broken internet connection before) using the new cable, and
the laptop using the old one.

I've written a little program which executes a command and prefixes each line
of its output with a timestamp. The command is "ping -i20".