VirtualBox for Mac OS: Install Debian 10

1. Download and install VirtualBox for Mac OS. It's available from http://download.virtualbox.org/virtualbox/
2. Download Debian 10 Small CD Installation ISO: https://cdimage.debian.org/debian-cd/current/amd64/iso-cd/debian-10.1.0-amd64-netinst.iso
3. Start VirtualBox and install Debian 10.
4. Download and install VirtualBox Guest Additions: http://download.virtualbox.org/virtualbox/6.0.12/VBoxGuestAdditions_6.0.12.iso
• Attach the VBoxGuestAdditions_6.0.12.iso to CDROM of the virtual machine
• Install required packages:

  sudo apt update -y && apt upgrade

  sudo apt install dkms linux-headers-$(uname -r) build-essential

• Install VirtualBox Guest Additions:

  sudo sh /media/cdrom0/VBoxLinuxAdditions.run

5. After installing VirtualBox Guest Additions, it's possible to change the screen resolution of the guest vm. However, the font size is too small in the guest VM Window. You can change the Display Scale Factor:
• Select the VM instance in VirtualBox, open "Settings" -> "Display", set "Scale Factor" to 150%
6. Set up "Shared Folders"
• After set up shared folders, you need to run the command below in the VM:

  sudo adduser $USER vboxsf

  and restart the VM.

See also

• Virtualbox shared folder permissions
• Install VirtualBox Guest Additions on Debian 10 Buster
• Debian 10: missing commands

uninstall chef-client

• On Ubuntu/Debian Linux:

  1. dpkg --list | grep chef

  2. sudo dpkg -P chef

• On RedHat/CentOS/Fedora Linux:

  1. rpm -qa *chef*

  2. sudo yum remove <chef-packages>

• On Mac OS X:

  1. sudo rm -fr /opt/chef

  2. sudo rm -f /usr/bin/chef-* /usr/bin/knife /usr/bin/ohai /usr/bin/shef

Citrix XenServer: failed to start Ubuntu VM after kernel upgrade

Recently I upgraded my Ubuntu VM to 12.04, which includes the new kernel. However the VM failed to reboot with following error:

Using  to parse /boot/grub/grub.cfg

To fix it,

1. boot your vm using the following command:

    xe-edit-bootloader -n your_vm_name -p 1

3. edit /grub/grub.cfg, comment out or remove the whole submenu section.

To avoid this, always remove the old kernels before rebooting. It automatically removes the submenu form grub.cfg. e.g.

aptitude remove linux-image-2.6.38-8-virtual

See also

• Ubuntu VM not starting on XenServer after kernel upgrade
• Ubuntu 11.04 boot failure after kernel upgrade because of submenu in grub.cfg

How to Virtualize OS X Lion on Windows

How to Virtualize OS X Lion on Windows: A blog post show how to install Mac OS X in VMWare Workstation running on Windows 7.