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Jun 6, 2017

Openstack using DevStack - Failed to fetch cdrom


While going over all the configuration needed with devstack for open stack and during the installation - after running ./ i received an error
"failed to fetch cdrom ...."

To solve this, go into /etc/apt
do 'sudo nano sources.list' and remove by using '#" the cd rom line.

Then start again the ./ and it will work

you just removed / disabled the cd rom

Hoped i helped,

Apr 27, 2017

Parameter CONFIG_CONTROLLER_HOST failed validation: Given host does not listen on port 22:

Hi ,

Happen to me during openstack installation on fedora 25.

Solution - start the sshd service

'sudo service sshd start'

Solved for me

Hoped it helps

Jul 25, 2016

ODroid c2 LibreElec

Hi All,

I bought the Odroid c2, wonderful piece of electronic. I bought it with ubuntu.
But once it came and after it requested to update and upgrade --> nothing works.
Then i tried manualy to install the ubuntu again it requested updates --> nothing works.
Then i tried the parallel version to the open elec i have on my pi 2, named also as Libre Elec.
This works good.


Sep 25, 2015

Oracle ORA-28000 Account is locked

Hi All,

This was the solution for me

su - oracle

sqlplus "/ as sysdba"

sql> alter user system account unlock;

--> System was my locked user, in your case replace system with you locked account user name. 

Hope it helped,


Sep 22, 2015

Fedora 22 VirtualBox


I have installed the latest fedora 22 and from some reason VirtualBox gave me tons of errors.

Looked all over the place and didn't find any good solution till now. So i wanted to share this with you to save you time, hopefully that you are seeing before all the searches i already did.

This is the required things to do:
This was my error

WARNING: The vboxdrv kernel module is not loaded. Either there is no module
         available for the current kernel (4.1.6-201.fc22.x86_64) or it failed to
         load. Please recompile the kernel module and install it by

           sudo /etc/init.d/vboxdrv setup

         You will not be able to start VMs until this problem is fixed.

 First , try to run this, with or without sudo
"/etc/init.d/vboxdrv setup"

if it went ok -> you are all good, probably virtualbox will run ok for you, for me it didn't helped.

If it didn't went ok, go over here :
I got this error
Stopping VirtualBox kernel modules                         [  OK  ]
Recompiling VirtualBox kernel modules/etc/init.d/vboxdrv: line 335: /var/log/vbox-install.log: Permission denied
  (Look at /var/log/vbox-install.log to find out what went wrong)

So i did as they say : "cat /var/log/vbox-install.log"
And got this:
Makefile:185: *** Error: unable to find the sources of your current Linux kernel. Specify KERN_DIR=<directory> and run Make again.  Stop.

So i did the following:
"sudo usermod -a -G vboxusers username" (you will replace username with your name of the user)
"su -"
" KERN_DIR=/usr/src/kernels/username" (replace username with your name of the user)
"export KERN_DIR"
"dnf install open-vm-tools"
"dnf -y install kernel-devel kernel-headers"
"sudo /etc/init.d/vboxdrv setup" -> this should be running ok now
You should receive something like me
Stopping VirtualBox kernel modules                         [  OK  ]
Recompiling VirtualBox kernel modules                      [  OK  ]
Starting VirtualBox kernel modules                         [  OK  ]

Good luck and hopefully that i helped a bit,


Feb 16, 2015

The BPEL process deployment session is already active.

Hi All,

Happens with Oracle Service Bus and Eclipse.

I have found, that stopping coherence and osb and then starting coherence and starting osb solved for me the issue.

Hoped it helped,

Oct 23, 2014

Infinispan listener event owner

It took me a while to find this, it exists from version 5.3 of infinispan.

I have a cluster and i want that only the instance which got that event and insert it into the cache will handle - in my case, save it to the db. Other replicated instances caches listeners won't work because in this particular event they aren't the owners .

You just need to annotate this above your listener : @Listener(primaryOnly = true)

See this for further information