Archive for the 'Korora' Category

Automatic power saving on a Linux laptop with PowerTOP and systemd

If you have a laptop and want to get more battery life, you may already know about a handy tool from Intel called PowerTOP.

PowerTOP not only monitors your system for interrupts but has a tunable section where you can enable various power saving tweaks. Toggling one such tweak in the PowerTOP interface will show you the specific Linux system command it ran in order to enable or disable it.

PowerTOP Tweaks

Furthermore, it takes an argument ––auto-tune which lets you enable all of the power saving measures it has detected.

Continue reading ‘Automatic power saving on a Linux laptop with PowerTOP and systemd’

Building a Mini-ITX NAS? Don’t buy a Silverstone DS380 case.

Edit: I made some changes which have dropped the temps to around 40 degrees at idle (haven’t tested at load yet). The case has potential, but I still think it’s slightly too cramped and the airflow is not good enough.

Here’s what I changed:

  • Rearranged the drives to leave a gap between each one, which basically limits the unit to 4 drives instead of 8
  • Inverted the PSU as per suggestion from Dan, so that it helps to draw air through the case. The default for the PSU is to draw air from outside and bypass the case.
  • Plugged the rear and side fans directly into the PSU molex connector, rather than through mainboard and rear of hard drive chassis

So I’m building a NAS (running Fedora Server) and thought that the Silverstone DS380 case looked great. It has 8 hot-swappable SATA bays, claims decent cooling with filters, neat form factor.


It requires an SFX PSU, but there are some that have enough juice on the 12v rail (although avoid the SilverStone SX500-LG, it’s slightly too long) so that it’s not a major problem (although I would prefer standard ATX).

So I got one to run low-power i3, C226 chipset mainboard and five HGST 3TB NAS drives. Unfortunately the cooling through the drives is pretty much non-existent. The two fans on the side draw air in but blow onto the hotswap chassis and nothing really draws air through it.

As a result, many of the drives run around 65 degrees Celsius at idle (tested overnight) which is already outside of the drives’ recommended temperature range of 0-60 degrees.

I’ve replaced the case with my second choice Fractal Design NODE 304 and the drives at idle all sit at around 35 degrees.


It has two smaller fans at the front to bring air directly over the drives and a larger one at the rear, with a manual L/M/H speed controller for all three on the rear of the case. As a bonus, it uses a standard ATX power supply and has plenty of room for it.

The only downside I’ve found so far is the lack of hot-swap, but my NAS isn’t mission-critical so that’s not a deal breaker for me.

Your mileage might vary, but I won’t buy the DS380 for a NAS again, unless it’s going to run full of SSDs or something (or I heavily mod the case). It’s OK for a small machine though without a bunch of disks (shame!) and that’s what I’ve re-purposed it for now.


Reset keyboard shortcuts in GNOME

Recently we had a Korora user ask how to reset the keybindings in GNOME, which they had changed.

I don’t think that the shortcuts program has a way to reset them, but you can use dconf-editor.

Open the dconf-editor program and browse to:


Anything that’s been modified should be in bold font. Select it then down the bottom on the right click the “Set to Default” button.

Hope that helps!

Korora 22 (Selina) available

We’ve finally had time to finalise Korora 22 and images are now available. I strongly recommend downloading with BitTorrent if you can.


We are not shipping Adobe Flash by default from 22 onwards, due to consistent security flaws. We still include the repository however, so users can install via the package manager or command line if they really want it:

sudo dnf install flash-plugin

Alternatively, install Google Chrome which includes the latest version of Flash.

Also, KDE 4 is not available for this release, so if you are not ready to move to KDE 5, then please stick to Korora 21.

Korora 21 available

It has taken a few weeks longer than we had hoped, but Korora 21 images are now available. I strongly recommend downloading with BitTorrent if you can.

The 21 beta was quite successful and we were able to make some minor changes to help improve the overall experience. Users who are currently on the beta need not re-install, updates are provided via the package manager. Users who are on 20 may consider upgrading, however this is not necessary as version 20 is supported for another 6 months or so.

Korora 21 beta images available

Korora 21 beta images are now available! Please leave a comment or ping me on social media with any issues or ideas so we can make it better.

Decorating (a)kmod packages with modalias info for use with RPM

Originally posted by firnsy at Korora Project news.

Whilst developing Pharlap, our utility for easing the installation and removal of drivers, we came across a big hurdle that other distributions had seemingly solved. The hurdle was being able to identify packages that provide support for a particular piece of hardware. Our initial workarounds used a dedicated map and for a while it was sufficient but it wasn’t ideal. Over time, the frustration of it’s inelegance grew and thus began our journey to investigate a more elegant solution.

Before developing Pharlap, there was Jockey, originally ported over from Ubuntu land by Hedayat Vatankhah for his Parsidora Fedora Remix. We started to contribute to and incorporate Hedayat’s work around version 16. At this time Hedayat, proposed the integration of Jockey into the RPM Fusion repositories which was met with a level of positivity. Could this already be implemented and we just don’t know? Darn, doesn’t look like it. Let’s continue.

So I mentioned earlier that other distributions had already solved this problem and indeed they had Debian/Ubuntu decorate their kernel module packages with the modaliases that the modules provide support for. Awesome? Yes it is! That allows the higher level package utilities to query the “provides” information using a device ID of interest.

So with that in mind, we set out to identify how we could adequately decorate kmod and akmod packages with appropriate modalias information.

kmod Packages

Starting with kmod packages (more specifically those rpm packages which contain pre-compiled kernel *.ko modules) it turns out that is reasonably trivial to decorate them using the builtin pluggable fileattr decorators of RPM with some post-processed information derived from ‘modinfo’.

To achieve this first build an appropriate “what provides” decorator that can interpret our kernel module files (*.ko). Fortunately this already exists in a standard installation but for reasons I’m not entirely sure of, is not enabled. So we just copy the modalias.prov out of the /usr/lib/rpm/redhat directory as a new file /usr/lib/rpm/kmod.prov.

Here’s the file for reference.

$ cat /usr/lib/rpm/kmod.prov
#! /bin/sh
# heavily based upon find-suggests.ksyms by Andreas Gruenbacher .
# with modifications by Michael Brown
# -- added module versioning info to modalias() symbols
# -- removed code which inspects spec files.
# Initially, dont generate modalias() lines for kernel package. This needs
# additional discussion. Would like to eventually add them for
# completeness, so that we can determine when drivers are folded into
# mainline kernel.
case "$1" in
kernel-module-*) ;; # Fedora kernel module package names start with
# kernel-module.
kernel*) is_kernel_package=1 ;;
if ! [ -z "$is_kernel_package" ]; then
cat > /dev/null
exit 0
print_modaliases() {
declare class=$1 variants=$2 pos=$3
if [ -n "$variants" ]; then
echo "${class:0:pos}[$variants]${class:pos+1}"
[ -z "$class" ] || echo "$class"
combine_modaliases() {
declare tag class variants pos n
read class
while read tag; do
for ((n=0; n<${#class}; n++)); do if [ "*" != "${class:n:1}" -a \ "${class:0:n}" = "${tag:0:n}" -a \ "${class:n+1}" = "${tag:n+1}" ] && ( [ -z "$pos" ] || [ $n = $pos ] ); then variants="${variants:-${class:n:1}}${tag:n:1}" pos=$n break fi done if [ $n -eq ${#class} ]; then print_modaliases "$class" "$variants" "$pos" variants= pos= class=$tag fi done print_modaliases "$class" "$variants" "$pos" }   for module in $(grep -E '/lib/modules/.+\.ko$') $*; do # | head -n1 because some modules have *two* version tags. *cough*b44*cough* modver=$(/sbin/modinfo -F version "$module"| head -n1) modver=${modver// /_}   # only add version tag if it has a version if [ -n "$modver" ]; then /sbin/modinfo -F alias "$module" \ | sed -nre "s,(.+),modalias(\\1) = $modver,p" else /sbin/modinfo -F alias "$module" \ | sed -nre "s,(.+),modalias(\\1),p" fi done \ | sort -u \ | combine_modaliases

We need to plug in our new provider by adding an attribute file in the /usr/lib/rpm/fileattrs directory. To follow suit, we'll call it kmod.attr which looks like this:

$ cat /usr/lib/rpm/fileattrs/kmod.attr
%__kmod_provides %{_rpmconfigdir}/kmod.prov
%__kmod_path ^/usr/lib/modules.*\\.ko$

The two lines indicate that any kernel module captured by %__kmod_path is to be passed onto the kmod.prov decorator.

So how does it look? Here's a listing of the provides for a kmod package built with the above changes:

$ rpm -qp --provides ./kmod-wl-3.13.10-200.fc20.x86_64-
kernel-modules-for-kernel = 3.13.10-200.fc20.x86_64
kmod-wl-3.13.10-200.fc20.x86_64 =
kmod-wl-3.13.10-200.fc20.x86_64(x86-64) =
wl-kmod =

Sweet, that looks exactly like what we want. So that takes care of kmods, what about akmods?

akmod Packages

Unfortunately the above method won't satisfy our initial requirement for akmods to also provide modalias information. The main reason is that akmod packages don't contain any pre-built kernel modules, they contain the source RPM from which a suitable kmod package can be built from.

Damn! Ideally, doing a "provides" search via dnf or yum should return both kmod and akmod packages.

We mentioned that an akmod package actually contains the source code and thus no directly suitable files (such as *.ko files) that can be interrogated by the fileattrs. Fortunately, akmod packages are produced by the same spec that is used to create the kmod packages and thus we have the ability to leverage some information to generate a dedicated file with sufficient information that can be interrogated for decoration at a later stage.

So looking at the typical structure of an akmod package it contains normally two files, the source RPM and a symlink to the latest source RPM (normally itself). Our proposal involves the addition of another file using similar unique naming to the source RPM (e.g. kmod-$name-$version-$release.modalias) that contains the associated modaliases that will be present when the kmod is built.

With the file in place, we can then perform a similar process to what we used for the kmod packages and ensure the decorator can process our new modalias file.

So in order to build this file, we need to unravel the complexities of how akmods are produced. I won't go into the nitty gritty but suffice to say there's a reasonable amount of magic provided by the kmodtool which does some dynamic macro creation for the kmod spec files. The final stages of these spec files, throws a call to %{?akmod_install}. It's this macro that we need to extend to create our modalias file. The following small diff is all that is needed to generate the .modalias file which we can then have picked up by an appropriate decorator.

$ diff -Nurd /usr/bin/kmodtool /tmp/kmodtool
--- /usr/bin/kmodtool 2013-12-08 04:17:24.000000000 +1100
+++ /tmp/kmodtool 2014-04-22 16:35:50.564309505 +1000
@@ -66,7 +66,14 @@
rpmbuild --define "_sourcedir %{_sourcedir}" \\\
--define "_srcrpmdir \$RPM_BUILD_ROOT/%{_usrsrc}/akmods/" \\\
-bs --nodeps %{_specdir}/%{name}.spec ; \\\
-ln -s \$(ls \$RPM_BUILD_ROOT/%{_usrsrc}/akmods/) \$RPM_BUILD_ROOT/%{_usrsrc}/akmods/${kmodname}-kmod.latest
+ln -s \$(ls \$RPM_BUILD_ROOT/%{_usrsrc}/akmods/) \$RPM_BUILD_ROOT/%{_usrsrc}/akmods/${kmodname}-kmod.latest ; \\\
+for kernel_version in %%{?kernel_versions}; do pushd _kmod_build_\${kernel_version%%___*} ; \\\
+for module in *.ko; do \\\
+ modver=\$(modinfo -F version "\$module"| head -n1) \\\
+ modver=\${modver// /_} \\\
+ [ -n "\$modver" ] && modinfo -F alias "\$module" | sed -nre "s,(.+),modalias(\\\\1) = \$modver,p" || modinfo -F alias "\$module" | sed -nre "s,(.+),modalias(\\\\1),p" ; \\\
+done >> \$RPM_BUILD_ROOT/%{_usrsrc}/akmods/${kmodname}-kmod-%{version}-%{release}.modalias ; \\\
+popd ; done
%package -n akmod-${kmodname}
Summary: Akmod package for ${kmodname} kernel module(s)

With our modalias file now being created, we need to build an appropriate decorator. The astute will notice that a portion of our original decorator has made it's way into the macro diff above. This in turn allows us to simplify the final decorator which in this case we call modalias.prov and place it in the /usr/lib/rpm directory.

$ cat /usr/lib/rpm/modalias.prov
#! /bin/sh
# heavily based upon find-suggests.ksyms by Andreas Gruenbacher .
# with modifications by Michael Brown
# -- modalias file already contains modalias information and just needs to
# be sorted and combined
print_modaliases() {
declare class=$1 variants=$2 pos=$3
if [ -n "$variants" ]; then
echo "${class:0:pos}[$variants]${class:pos+1}"
[ -z "$class" ] || echo "$class"
combine_modaliases() {
declare tag class variants pos n
read class
while read tag; do
for ((n=0; n<${#class}; n++)); do if [ "*" != "${class:n:1}" -a \ "${class:0:n}" = "${tag:0:n}" -a \ "${class:n+1}" = "${tag:n+1}" ] && ( [ -z "$pos" ] || [ $n = $pos ] ); then variants="${variants:-${class:n:1}}${tag:n:1}" pos=$n break fi done if [ $n -eq ${#class} ]; then print_modaliases "$class" "$variants" "$pos" variants= pos= class=$tag fi done print_modaliases "$class" "$variants" "$pos" }   while read FILE; do cat $FILE done | sort -u | combine_modaliases

We hook up the modalias decorator by adding a modalias.attr attribute file in the /usr/lib/rpm/fileattrs directory, which looks like the following:

$ cat /usr/lib/rpm/fileattrs/modalias.attr
%__modalias_provides %{_rpmconfigdir}/modalias.prov
%__modalias_path ^/usr/src/akmods/.*\\.modalias$

And the final result yields:

$ rpm -qp --provides ./akmod-wl-
akmod-wl =
akmod-wl(x86-64) =
wl-kmod =


OK, so what now? Well this is just the results of us investigating if it was possible and how it could be done. The above mechanism would require a diff to the kmodtool and rpm-build packages to provide the auto-decorating of modalias information on kmod and akmod packages.

Knowing that this can work, we think it might be a good time to revisit the possibilities with the RPMFusion team and see if we can make this a reality that all users of RPMFusion packages can benefit from.

Stay tuned!

Fix problem updating packages in Fedora/Korora due to broken SELinux update

Unfortunately an update to the SELinux policy package in Fedora 20 (and therefore Korora 20) caused RPM scriptlets to fail when updating packages.

This bug only affects systems that have SELinux mode set to enforcing (which is the default) and were updated to version 3.12.1-116 of the selinux-policy package. If you have seen the following sort of error when updating packages, then this bug may affect you:

warning: %post(libkcompactdisc-4.12.1-1.fc20.x86_64) scriptlet failed, exit status 127
Non-fatal POSTIN scriptlet failure in rpm package libkcompactdisc-4.12.1-1.fc20.x86_64

Below are the commands to resolve this issue (which has been fixed in an updated 3.12.1-117 version of selinux-policy).

sudo setenforce 0
sudo yum clean expire-cache
sudo yum update selinux-policy\*
sudo setenforce 1

The first command disables SELinux enforcement for the current session and the subsequent commands expire the yum cache and install the SELinux policy update which fixes this issue. The last command re-enables SELinux enforcement.

If you previously installed any packages which failed with scriptlet errors like above, you can reinstall them using the following command:

sudo yum reinstall

You can find out what packages were installed after the broken update using a command like this:

sudo sed '1,/selinux-policy-3.12.1-116/d' /var/log/yum.log

If you require any assistance please don’t hesitate to ask for help using Engage or jump onto the #korora channel in IRC servers.

Force rsync to use delta transfer to fix corrupt remote file

We host our Korora Project ISO images on SourceForge and I (naturally) use rsync to move them there (slowly, at 100kb/sec). Sometimes though the connection drops off and that’s OK because rsync picks up where it left off.

However occasionally the ISO ends up with the wrong checksum, so something went wrong in the transfer. No amount of re-rsyncing seems to fix this up because by default it uses file size and timestamps to check whether it should skip existing files.

Fortunately, I don’t need to re-send the whole file again as rsync can perform a delta transfer instead and only send the small difference. Yay!

The way I do this is by passing a combination of options to rsync, such as –checksum (to enable transfer of the file), –in-place (to transfer the file in place as rsync normally writes a temporary file, then moves) and –no-whole-file (which tells rsync to not copy the whole file, but use deltas instead).

This becomes something like:
rsync -Pa --checksum --inplace --no-whole-file local.file remote.server:

Here’s a real example:
chris@x220 ~ $ rsync -Pa --checksum --inplace --no-whole-file -e ssh korora-20-i386-cinnamon-live.iso csmart,
sending incremental file list
  1,715,470,336 100% 220.87MB/s 0:00:07 (xfr#1, to-chk=0/1)

So rsync just saved me 4 hours of uploading the ISO again. Thanks rsync.

Korora 20 (Peach) released

Today we released the final images for Korora Project (Fedora1 Remix) version 20 with Cinnamon, GNOME, KDE, MATE and Xfce desktops (in 32 and 64 bit).

The release was a little delayed because we were waiting for a few bug fixes to land, as well as Christmas and New Year holidays which got in the way.

We have also been hard at work building our new open source web platform which includes a replacement for our forums which is called Engage. Anyone who had an account with our old forums can log in to the new site, you will just get an email to activate your account first. Bug reports welcome!

1 Korora is not provided or supported by the Fedora Project. Official, unmodified Fedora software is available through the Fedora Project website.