Tag: command-line

How to run QEMU full virtualization with MacVTap networking using NetworkManager under CentOS 8

In addition to the previously presented article on the subject Howto do QEMU full virtualization with MacVTap networking this one shows how to run a QEMU virtual machine with a MAcVTap device in bridge mode on the host server configured only by using the NetworkManager cli – nmcli.

It is worth mentioning the MacVTap is a virtual bridge, which will make the host and the guest device show up directly on the host switch. So when using QEMU, the guest virtualized system will be as if it is connected to the host switch with one limitation – the host and guest cannot communicate with each other. The IPs of the host won’t be reachable from the guest, so NAT (masquerade) between the host and guest is not possible with this setup. Still, if the NAT server is on another server or a real IP is planned for the guest, MacVTap is the right functionality to use with the QEMU guest system.

Summary

  1. Add MacVTap device in bridge mode with name macvtap0.
  2. Install QEMU.
  3. Create QEMU local disk.
  4. Run a QEMU virtual server.

STEP 1) Add MacVTap device in bridge mode with name macvtap0

[root@srv ~]# nmcli connection add type macvlan dev enp0s3 mode bridge tap yes ifname macvtap0 con-name macvtap0 ip4 0.0.0.0/24
Connection 'macvtap0' (7a5ef04c-ea98-4642-ac5d-4239f715f631) successfully added.
[root@srv ~]# nmcli con
NAME      UUID                                  TYPE      DEVICE   
enp0s3    09497bbf-da59-42b7-a72c-d69369760b36  ethernet  enp0s3   
macvtap0  7a5ef04c-ea98-4642-ac5d-4239f715f631  macvlan   macvtap0

First, create a MacVTap device with the name macvtap0 in bridge mode with the network interface enp0s3 a and a connection with the name macvtap0. The IP is set to manual mode.
More detailed information on how to create and add MacVTap device with the NetworkManager here – Create MacVTap device using NetworkManager nmcli under CentOS 8

STEP 2) Install QEMU.

Install the QEMU virtual tools under CentOS 8 Stream. At present, the QEMU version is 6.2, which is pretty new.
Keep on reading!

Installing conda command line in various systems with miniconda and create a simple python environment

Conda is yet another package, dependency and environment management for multiple languages like Python, C/C++, JavaScript, Java, Scala and many more
For example, with Conda the user could create python environment with the exact versions he needs! And it could be used under any Linux distribution or even Windows.

This article is to show how to install the command-line version of the Conda, which is part of the bigger platform Anaconda. The command-line version is distributed with the name Miniconda. In fact, Miniconda is a free installer for Conda, which includes only the basic set to run conda and conda install to install more than 8000 packages from the Anaconda repositories.

The Anaconda repositories could be found here: https://anaconda.org/anaconda/repo

Advantages of Miniconda:

  1. Minimal installation. 400 Mbytes, not 3G for the Anaconda platform.
  2. simple command-line interface. Couple of simple commands and their instructions are enough to bring up a complex environment for scientific or development purposes.
  3. The creating of a specific environment could be automated.
  4. No strange or not friendly GUI.
  5. Easy installation under most of the Linux distribution and Windows.
  6. The whole installation could occur only under a user’s home directory. No files require to be installed by the administrator or under global administrative path.

Keep on reading!