Failed to acquire the VirtualBox COM object.

It appears that the issue could be a corrupt VirtualBox.xml file. The one I had did not have anything in it. Removing or moving the file let it create a new one and let VirtualBox actually start.

mv ~/.config/VirtualBox/VirtualBox.xml{,old}

Only problem is that none of the VM’s showed up. Was able to go to the ~/VirtualBox folder in a file browser and launch the vbox file to start the VM

Where is the Trash in KDE?

Where are the trash files stored?

The file location for the trash is in the following directory

~/.local/share/Trash/

Inside there are two folders. info and files.
info – Keeps track of what was deleted and where it was
files – Contains the actual files

Delete the files in the Trash

  • First delete the file in the “info” directory
  • Then go delete the files in the “files” directory

To delete the files, select the files then press “Shift + Del”
or right click, hold Shift down and select Delete.

Bash random sleep timer

Change the 10 to however many seconds you need or want.

echo $(( ( RANDOM % 10 ) +1 ))

Example output

bob@localhost:~$ echo $(( ( RANDOM % 10 ) +1 ))
10
bob@localhost:~$ echo $(( ( RANDOM % 10 ) +1 ))
2
bob@localhost:~$ echo $(( ( RANDOM % 10 ) +1 ))
9
bob@localhost:~$ 

Sleep timer

sleep $(( ( RANDOM % 10 ) +1 ))

kubuntu-desktop : Depends: software-properties-kde but it is not going to be installed

Try installing software-properties-kde and get

The following packages have unmet dependencies:
  software-properties-kde : Depends: python3-software-properties (= 0.96.24.32.11) but 1.8.8 is to be installed
 E: Unable to correct problems, you have held broken packages.

Try to install python3 from the bionic from bionic-updates

sudo apt install -t bionic-updates python3-software-properties

Install software-properties-kde

sudo apt install software-properties-kde

If it fails try force installing it

sudo dpkg -i --force-overwrite /var/cache/apt/archives/software-properties-kde_0.96.24.32.11_all.deb

Install Kubuntu desktop

sudo apt install kubuntu-desktop

More info here
https://pravin517.wordpress.com/2019/07/14/kubuntu-desktop-depends-software-properties-kde-but-it-is-not-going-to-be-installed/

Install KDE on Linux Mint 19.2

First add the following repo

sudo add-apt-repository ppa:kubuntu-ppa/backports

Make sure you are updated and upgraded

sudo apt-get update && sudo apt-get dist-upgrade

And if needed do a reboot

sudo reboot

Install the KDE desktop

sudo apt install kubuntu-desktop

Log out, select Plasma and log back in.

https://computingforgeeks.com/how-to-install-kde-plasma-desktop-on-linux-mint-19/

Setup DHCP server on Linux

Install dhcp server software

sudo apt install isc-dhcp-server

Edit the following config file and set the networking interface it should use. In this case enp60s0

sudo vi /etc/default/isc-dhcp-server

Example line to change

INTERFACESv4="enp60s0"

Now edit the dhcpd.con file

sudo vi /etc/dhcp/dhcpd.conf 

Add the following in. Change the addresses and settings as needed.

subnet 192.168.47.0 netmask 255.255.255.0 {
   range 192.168.47.26 192.168.47.30;
   option domain-name-servers ns1.internal.example.org;
   option domain-name "internal.example.org";
   option subnet-mask 255.255.255.0;
   option routers 192.168.47.1;
   option broadcast-address 192.168.47.255;
   default-lease-time 600;
   max-lease-time 7200;
 }

Set a static ip on the computer that’ll be acting as the dhcp server. You can set it as the gateway if it is the gateway.

Allow dhcp through the firewall

sudo ufw allow  67/udp
sudo ufw reload
Restart the service and connect a client.

sudo systemctl restart isc-dhcp-server

More info.

You can look at dhcp leases with the following command

tail -f /var/lib/dhcp/dhcpd.leases

How to reset Minecraft Demo timer without resetting the World – Linux

Note that the following commands have not been tested, but based off of other ones so should work.

Open a terminal and run the following two commands to delete level.dat and level.dat_old

rm ~/.minecraft/saves/Demo_World/level.dat 
rm ~/.minecraft/saves/Demo_World/level.dat_old 

Should be able to open up Minecraft and have the timer reset. Note that all the achievments in the game will be reset as well.

How To Reset root Password on CentOS VM – XenServer

Basic steps are as follows.

  1. Shutdown VM
  2. From XenCenter, insert the CentOS iso into the VM’s Virtual DVD drive.
  3. Boot the CentOS VM in recovery mode.  If you need help with that check this post out.
  4. On the grub menu, select recover OS Installation.
  5. Run through the recovery and mount the VM’s disk where CentOS is installed
  6. You should now be able to drop to a prompt and chroot /sysimage
  7. Change the root password with passwd
  8. Shutdown the VM
  9. Eject the CentOS iso
  10. Boot up the VM and login with the new password