Running LXDE inside Xephyr in Arch Linux

Install Xephyr:

sudo pacman -S xorg-server-xephyr

Install LXDE:

sudo pacman -S lxsession-gtk3 lxpanel-gtk3 pacmanfm-gtk3 openbox lxtask-gtk3 lxde-icon-theme lxterminal-gtk3 lxrandr-gtk3

Then run Xephyr:

Xephyr -ac -noreset -query localhost -screen 1920x1080 -keybd ephyr,,,xkbmodel=evdev :3

And in another terminal:

DISPLAY=:3 startlxde

D-Bus user session

I noticed that I cannot open the user dbus in Ubuntu while I could do that in Arch Linux. It seems there is no user dbus by default in Ubuntu (or Ubuntu server at least). To have one:

$ sudo apt install dbus-user-session

Then `sudo systemctl start --user dbus` or reboot.

Mysterious crashes in DPDK application when using the pcap driver.

I was experiencing mysterious crashes in my DPDK application when using pcap virtual devices (using the --vdev option). What's more, when there was more crashes, I didn't seem to be getting all the packets I should have. So I investigated, and found out I was attempting to capture packets from multiple threads. That seems to be a no no with the pcap driver, considering it explicitly does not support multiple queues. I limited the number of cores available to my application using the -c option, and everything was solved.

Fixing "no driver found for eth_pcap0"

I was getting a "no driver found for eth_pcap0" error message whenever I wanted to use an "eth_pcap" virtual device with my DPDK application. But the DPDK sample app "test-pmd" worked just fine with those. So I took a look at its Makefile and found out adding this line to my Makefile fixes the issue:

DEPDIRS-y += lib drivers

ISO seems to be empty in Linux

So I had this ISO that I knew wasn't corrupted because I've seen it mounted and used on a Windows machine. In Linux though, mount gave me a "wrong fs type" error and both Archive Mounter and Archive Manager said the ISO is empty.

A quick search brought me to this Ubuntu Forums thread that gave me the answer. The ISO was in the UDF format. This is how I managed to mount it: sudo mount -t udf -o loop ~/path/to.iso mountdir

Enabling temperature sensors in Ubuntu

After installing lm-sesnors, you can see the current value of system sensors by running "sensors". If you suspect your system has more sensors than "sensors" is showing you, run "sensors-detect" and have it scan for more sensors. Then when it asks you if you want appropriate modules added to your /etc/modules file, say yes. Restart your computer and check "sensors" again.

Emacs configure script not finding gnutls even though you have it.

You probably don't have pkg-config installed. At least that was the case for me in my new Arch install. I just did a `sudo pacman -S pkg-config`, then configured emacs again.