Tag Archives: fedora

ReadyMedia multicast discovery on bridge iface

When running a ReadyMedia (aka MiniDLNA, but it could be the case for any application using multicast) server on a bridged interface (like br0), multicast_snooping must be disabled on the bridge:

echo 0 > /sys/devices/virtual/net/br0/bridge/multicast_snooping

to make the change permanent:

echo 'net.br0.bridge.multicast_snooping=0' > /etc/sysctl.d/98-minidlna_no_snoop.conf

References:

QGIS latest on Fedora stable

If you are looking for the latest version of QGIS for your stable Fedora installation (24 and 25 as writing) you can simply add my COPR repo: https://copr.fedorainfracloud.org/coprs/dani/QGIS-latest-stable/

sudo dnf copr enable dani/QGIS-latest-stable
sudo dnf install qgis

This repo includes the latest stable QGIS (backported from rawhide when available, otherwise built from scratch) with few changes.

Source of RPM packages can be found here: https://daniele.vigano.me/git/dani/copr-dani-qgis

CentOS 7 LXC container slow boot

After you have installed a CentOS 7 LXC template on a systemd supprted distro (Fedora 21/22, CentOS 7 with LXC 1.0.7), you can experience a ultra slow container boot (more than 5 minutes!). A small change can fix this issue.

In the container config (i.e. /var/lib/lxc/centos7/config) replace:

1
lxc.include = /usr/share/lxc/config/centos.common.conf

with

1
lxc.include = /usr/share/lxc/config/fedora.common.conf

This will make the container boot fast as it should be.

centos.common.conf is fine for CentOS 6 but not for CentOS 7: CentOS 7 is based on Fedora 19 and uses systemd, thus fedora.common.conf is the right config file to use.

Fedora 22 / CentOS 7 LXC fix systemd-journald process at 100%

Running a Fedora 21, Fedora 22 or a RHEL/CentOS 7 LXC container created by the lxc-create Fedora template can result in a 100% cpu loop for the systemd-journald process.

To fix this issue you must add lxc.kmsg = 0 to the container configuration. This can be done easily for all the Fedora templates in one shot:

echo "lxc.kmsg = 0" >> /usr/share/lxc/config/fedora.common.conf

See also:

Disable background updates on Fedora 21 / GNOME 3.14

If you use frequently a mobile internet connection with a monthly traffic limit, like me, you probably want control over automatic updates to avoid wasting traffic data.

GNOME 3.14 has a feature to automatically check for new updates using its gSoftware application. This feature can be disabled using the gsettings command line tool:

$ gsettings set org.gnome.software download-updates false

If you are not familiar with the terminal, also the graphical dconf-editor can be used.

First you need to install it:

$ sudo yum install dconf-editor

then, as normal user run it:

$ dconf-editor

now navigate to org.gnome.settings-daemon.software schema and un-tick the download-updates flag:

dconf-editor-updates

If you are using an older version of GNOME the schema is slight different. For Fedora 20/GNOME 3.10 you can take a look at this post http://worldofgnome.org/fedora-20-gnome-software-tips-and-tricks/.

Create a new Fedora LXC container using yum

In this tutorial we are going to install an LXC container with Fedora 21 to be run on a Fedora 21 host with libvirt. This can be used to create containers to be managed by my WebVirtMgr web panel.

Install the new filesystem

yum -y --installroot=/var/lib/libvirt/filesystems/fedora21 --releasever=21 --nogpg install systemd passwd yum fedora-release vim openssh-server procps-ng iproute net-tools dhclient less

Create the libvirt domain

virt-install --connect lxc:/// --name fedora21 --ram 512 --filesystem /var/lib/libvirt/filesystems/fedora21/,/

This command will also start the domain. Now it’s time to stop it and do some post install configurations.

Post-installation setup

Press Ctrl + ] to detach from the domain console. Than stop it:

virsh -c lxc:/// shutdown fedora21

Change root password

chroot /var/lib/libvirt/filesystems/fedora21 /bin/passwd root

Setup the hostname

echo "mynewlxc" > /var/lib/libvirt/filesystems/fedora21/etc/hostname

Setup the network

cat << EOF > /var/lib/libvirt/filesystems/fedora21/etc/sysconfig/network
NETWORKING=yes
EOF
cat << EOF > /var/lib/libvirt/filesystems/fedora21/etc/sysconfig/network-scripts/ifcfg-eth0
BOOTPROTO=dhcp
ONBOOT=yes
DEVICE=eth0
EOF

Setup SSH

chroot /var/lib/libvirt/filesystems/fedora21/
ln -s /usr/lib/systemd/system/sshd.service /etc/systemd/system/multi-user.target.wants/
exit

Start the container

virsh -c lxc:/// start fedora21

Or, if you are using my WebVirtMgr web panel fork you can start / stop the domain using it.

The Fedora 21 LX

The Fedora 21 LXC

Source

Thanks to major.io for his original article. It contains also some important considerations about security.

HP MicroServer + RAC on Fedora 18

After upgrading my HP MicroServer with Remote Access Card from Fedora 17 to Fedora 18 (kernel-3.8.3-203.fc18) the RAC KVM console (remote and VGA) stopped to work with ‘out-of-range’ signal after:

[ 4.072580] [drm] Initialized drm 1.1.0 20060810
[ 4.104362] [drm] AST 1100 detected
[ 4.104500] [drm] dram 816000000 1 16 04000000
[ 4.104785] [TTM] Zone kernel: Available graphics memory: 2024944 kiB
[ 4.104913] [TTM] Initializing pool allocator
[ 4.105035] [TTM] Initializing DMA pool allocator
[ 10.522147] [sched_delayed] sched: RT throttling activated

The MicroServer RAC has an AST1100 video controller that currently doesn’t work very well with the Linux KMS (Kernel Mode Setting).

HP RAC KVM out of sync

 

So, to fix this issue you need to disable the KMS for the ast module:

  • Edit /etc/sysconfig/grub and at the end of the GRUB_CMDLINE_LINUX line add “ast.modeset=0 nomodeset
    GRUB_CMDLINE_LINUX="rd.md=0 rd.lvm=0 rd.dm=0 SYSFONT=latarcyrheb-sun16 rd.luks=0 KEYTABLE=it LANG=en_US.UTF-8 ast.modeset=0 nomodeset quiet"
  • Update the grub2 configuration
    grub2-mkconfig -o /boot/grub2/grub.cfg

OPTIONAL

  • Create /etc/modprobe.d/ast.conf with
    options ast modeset=0
  • Update the initramfs with dracut
    dracut --force

The bug has been reported at RedHat Bugzilla bug #926064.

References:
modinfo ast:

filename:       /lib/modules/3.8.3-203.fc18.x86_64/kernel/drivers/gpu/drm/ast/ast.ko
license:        GPL and additional rights
description:    AST
author:         Dave Airlie
alias:          pci:v00001A03d00002010sv*sd*bc03sc*i*
alias:          pci:v00001A03d00002000sv*sd*bc03sc*i*
depends:        drm,drm_kms_helper,ttm,i2c-core,i2c-algo-bit
intree:         Y
vermagic:       3.8.3-203.fc18.x86_64 SMP mod_unload
parm:           modeset:Disable/Enable modesetting (int)

Installing ObsPy on Fedora 18

obspy-logo

ObsPy is an open-source project dedicated to provide a Python framework for processing seismological data. It provides parsers for common file formats, clients to access data centers and seismological signal processing routines which allow the manipulation of seismological time series (see Beyreuther et al. 2010, Megies et al. 2011).

The goal of the ObsPy project is to facilitate rapid application development for seismology.

https://github.com/obspy/obspy/wiki

ObsPy packages are available only for Debian/Ubuntu, however is possible to install it on Fedora via Python Package Index (PyPI). Not all deps are explained on ObsPy wiki pages so here is the complete procedure to install the software on Fedora 18:

First set up all the dependencies via yum

[root@sam ~]# yum install -y python-devel python-setuptools numpy scipy python-matplotlib python-matplotlib python-matplotlib gcc-gfortran python-suds python-sqlalchemy python-lxml

Now you can install ObsPy as explained in theirs wiki (https://github.com/obspy/obspy/wiki/Installation-on-Linux-via-PyPI)

[root@sam ~]# easy_install -U distribute; easy_install -N obspy

To test if the installation was successful use obspy-runtests

[daniele@sam ~]$ obspy-runtests
................................................................................................................................................................................................s.....................................................
[...]
----------------------------------------------------------------------
Ran 839 tests in 65.348s
 
OK

That’s all.

References: