Daniel Lange's blog

Xfce 4.12 as default in Ubuntu/Xubuntu 18.04 LTS did not suspend a laptop after closing the lid. In fact running xfce4-power-manager --quit ; xfce4-power-manager --no-daemon --debug showed that xfce4 wasn't seeing a laptop lid close event at all.

To the contrary acpi_listen nicely finds button/lid LID close and button/lid LID open events when folding the screen and opening it up again.

As so often the wonderful docs / community of Arch Linux to the rescue. This forum thread from 2015 received the correct answer in 2017:

Xfce4 basically recognizes systemd and thus disables its built-in power-management options for handling these "button events" (but doesn't tell you so in the config UI for power-manager). Systemd is configured to handle these events by default (/etc/systemd/logind.conf has HandleLidSwitch=suspend but for unknown reasons decides not to honor that).

So best is to teach Xfce4 to handle the events again as in pre-systemd times:

xfconf-query -c xfce4-power-manager -p /xfce4-power-manager/logind-handle-lid-switch -s false

Now the UI options will work again as intended and the laptop suspends on lid close and resumes on lid open.

Update:

07.01.19: Changed XFCE -> Xfce as per Corsac's suggestion in the comments below. Thank you!

Background info:

The name "XFCE" was originally an acronym for "XForms Common Environment", but since that time it has been rewritten twice and no longer uses the XForms toolkit. The name survived, but it is no longer capitalized as "XFCE", but rather as "Xfce". The developers' current stance is that the initialism no longer stands for anything specific. After noting this, the FAQ on the Xfce Wiki comments "(suggestion: X Freakin' Cool Environment)".

(quoted from Wikipedia's Xfce article also found in the Xfce docs FAQ).

Firefox on Linux can develop the habit to (rather randomly) ask again and again to be made the default browser. E.g. when started from Thunderbird by clicking a link it asks but when starting from a shell all is fine.

The reason to this is often two (or more) .desktop entries competing with each other.

So, walkthrough: (GOTO 10 in case you are sure to have all the basics right)

should both show firefox for you. If not

the entry to fix the preference on /usr/bin/firefox.

Check (where available)

that the "Internet Browser" is "Firefox".

Check (where available)

that anything containing "html" points to Firefox (or is left at a non-user set default).

Check (where available)

that you get firefox.desktop. If not run

If you are running Gnome, check

and the same for https.

LABEL 10:

Run

and remove all entries that contain something like userapp-Firefox-<random>.desktop.

Run

and delete these files or move them away.

Done.

Once you have it working again consider disabling the option for Firefox to check whether it is the default browser. Because it will otherwise create those pesky userapp-Firefox-<random>.desktop files again.

Configuring Linux is easy, innit?

We're currently installing a solution including dovecot for a company to go into production in April. So we kick this off with a development box for integrating parts that different suppliers to our customer are working on.

But after installing dovecot on the new joint development machine it just didn't start. It worked on our local development boxes but the install for the customer has been scripted with (what we call) "poor man's puppet" so it is somewhat hard to compare the setups. Same Ubuntu 14.04 LTS under the hood but on top of that things (like config layout, directory structures etc.) are quite different.

Back on topic: ps aux | grep d[o]ve returned empty.

Looking at /var/log/mail.log did not show anything relevant.

But syslog (/var/log/syslog) had some worrying lines like:

Mar 16 03:16:17 dev-new kernel: [ 3222.339365] doveconf[6420]: segfault at 200 ip 00007fa041b25a03 sp 00007ffe7881e070 error 4 in libc-2.19.so[7fa041ada000+1bb000]

Manually running the daemon resulted in:

# /usr/sbin/dovecot -F -c /etc/dovecot/dovecot.conf
Segmentation fault

So

mkdir /var/core
chmod 1777 /var/core
echo "/var/core/%p" > /proc/sys/kernel/core_pattern
ulimit -c unlimited
/usr/sbin/dovecot -F -c /etc/dovecot/dovecot.conf
Segmentation fault (core dumped)

Better. We have a core file now.

But:

Manually copying the BIND master zone configuration to slave servers is a tedious and error-prone process. There are configuration management systems available for large deployments and BIND can support database backends as well which allow synchronization virtually behind the scenes.

For my use these options are overly complex and have unwanted risks associated with it.

The better option is to automate generating the BIND slave configuration from the BIND master named.conf.local.