Why Hyper-V virtual machines are not always available over the network

Suppose the server has one network card and in network connections it can be seen as “Ethernet”, but after adding the Hyper-V role, a virtual switch vEthernet (…) is created.

Virtual machines can be seen from other computers but can not be seen from the local.

Therefore, for virtual machines to be accessible from the local machine, you must disable the DHCP client to Ethernet, or assign an IP address manually, then the virtual switch vEthernet (…) will receive IP instead of Ethernet because they have the same The MAC address.

Solving the error of “Interface (‘VirtualBox Host-Only Ethernet Adapter’) is not a Host-Only Adapter interface”

I noticed once in VirtualBox when starting a virtual machine the following error:

Interface (‘VirtualBox Host-Only Ethernet Adapter’) is not a Host-Only Adapter interface (VERR_INTERNAL_ERROR).

As it turned out in the device manager of the system and in network connections for some reason, the network interface disappeared “VirtualBox Host-Only Network

For this, the easiest and fastest solution to an error will be to update or reinstall VirtualBox, virtual machines and settings will remain thereafter.
And also in the virtual machine, at which start there was an error, nano to specify the same network parameters.


Solution of VirtualBox error “Kernel driver not installed (rc=-1908)”

I noticed somehow an error in VirtualBox working on Linux Ubuntu Desktop 16.04:

Kernel driver not installed (rc=-1908)
The VirtualBox Linux kernel driver (vboxdrv) is either not loaded or there is a permission problem with /dev/vboxdrv. Please install virtualbox-dkms package and load the kernel module by executing
‘modprobe vboxdrv’
as root. If it is available in your distribution, you should install the DKMS package first. This package keeps track of Linux kernel changes and recompiles the vboxdrv kernel module if necessary.
where: suplibOsInit what: 3 VERR_VM_DRIVER_NOT_INSTALLED (-1908) – The support driver is not installed. On linux, open returned ENOENT.

To solve the problem it was necessary to disable the secure boot in the BIOS, in my case “Windows UEFI” was selected, changed to “Other OS”.
Then, after running the system, executed the command from the root user:

modprobe vboxdrv

In Ubuntu, you can switch to root as follows:

sudo -i

Done, the error is solved.

The solution to the error “Virtual machine could not be started because the hypervisor is not running”

I noticed once on one HP server, after installing Hyper-V, that virtual workstations are not being launched, giving the following error:

Hyper-V Manager
An error occurred while attempting to start the selected virtual machine(s).

Virtual machine could not be started because the hypervisor is not running.

As it turned out, the problem was in the Intel (R) Virualization Tech not activated in BIOS, after changing from “Disabled” to “Enabled” and start the system, the virtual workstations were successfully launched.

How to fix error VirtualBox “Unable to boot – please use a kernel appropriate for your CPU”

After running the virtual system in VirtualBox, I noticed the following error:

This kernel requires the following features not present on the CPU:
Unable to boot – please use a kernel appropriate for your CPU.

The error can be solved in several ways:

Method 1) When you turn on the computer, go into the BIOS and enable the virtualization in the processor settings (if the processor supports it).

Method 2) After opening VirtualBox, we will go into the settings of the virtual system created, namely “Settings” – “System” – “CPU” and put a tick near “Additional Options: Enable PAE/NX“. Click “OK” to save changes.

Done, this error should not be displayed.