No thumbnails for video previews in Nautilus.

As the default CentOS 7 / Gnome 3 video player, Totem, does not support many of the video formats in use today, thumbnails are not being generated by Nautilus.  (Nautilus uses the Totem player to generate these).  There are two causes to this problem:

1) The mp4,mkv and other formats are not supported by Totem and specific codecs need to be installed.  As posted in the Fedora Forums here are some of the codecs that need to be installed for this to work properly: https://ask.fedoraproject.org/en/question/9267/thumbnail-for-videos-in-nautilus/

yum -y install gstreamer1-libav gstreamer1-plugins-bad-free-extras gstreamer1-plugins-bad-freeworld gstreamer1-plugins-base-tools updates gstreamer1-plugins-good-extras gstreamer1-plugins-ugly gstreamer1-plugins-bad-free gstreamer1-plugins-good gstreamer1-plugins-base gstreamer1

Delete the following directory:

rm -r ~/.cache/thumbnails/fail
 
Logout and log back in, just to make sure Gnome takes the new plugins.  This step may not be necessary, but it may help.

The next thing to do is to increase the size of the files for which Nautilus can generate thumbnails.  By default this is set to 1MB.  (NOTE: Gnome does not recommend increase this size too much due to the impact it will have on performance.  However, the speed at which the thumbnails are generated is largely dependent on the file format of the videos: MP4s are done very quickly, while FLVs take much longer.)  To increase this, navigate to "File"->"Preferences"->"Preview" and change the "Only for files smaller than:" to whichever size you prefer.  I've set mine to 4GBs and performance seems fine.

Bootloader bug with system-config-kickstart

Here is another minor bug with system-config-kickstart:

During the opening of an existing kickstart configuration file, the application fails to read or load the bootloader configuration.  If this isn't reconfigured within kickstart, saving the file will set the bootloader directive to:

bootloader --location=none --boot-drive=<disk device=>

The location option should have been populated with those from the original file when it was read.

Best thing to do is to double check all of the basic settings once the kickstart config file is created (and saved) and manually edit whatever needs to be adjusted.

system-config-kickstart error in CentOS 7

Using system-config-kickstart version 2.9.6-1.el7 in CentOS 7 yields the following error, when attempting to select packages.

"Package selection is disabled due to problems downloading package information."

Screenshot of the message in the "Package Selection" menu.

It seems someone filed a bug with CentOS regarding this problem:  See https://bugs.centos.org/view.php?id=9611

As stated by the bug poster, the issue can be fixed by modifying line 161 of the file: /usr/share/system-config-kickstart/packages.py

156         # If we're on a release, we want to try the base repo first.  Otherwise,
157         # try development.  If neither of those works, we have a problem.
158         if "fedora" in map(lambda repo: repo.id, self.repos.listEnabled()):
159             repoorder = ["fedora", "rawhide", "development"]
160         else:
161             repoorder = ["rawhide", "development", "fedora"]

Becomes:

161             repoorder = ["rawhide", "development", "fedora", "base"]

Restart system-config-kickstart and packages can now be read from the local yum repositories.

Spacewalk 2.6 Notes

Allow Spacewalk control over remote configuration files:

/usr/bin/rhn-actions-control --enable-all

Otherwise if the permissions are not set, the scheduled task will fail with the following error kept in the log:

Local permission not set for action type configfiles.deploy

-- more to come --