Different alternatives exists to manage kvm guests:

  • Cockpit Webgui - Limited functionality, works in any webbrowser after enabling webgui and the webgui virtualization plugin on the server
  • Virt-manager GUI - deprecated yet "feature complete" for its last supported rhel version, works great for other distros, only installable on linux works for remote virtualization servers
  • Virsh command line CLI - always updated with the latest functionality, works inside the server, steeper learning curve than gui yet more features unavalible in the gui

At the time of writing the cockpit webgui lacks features provided in the virt-manager application. The deprecation tag on the virt-manager project is for RHEL only and does not mean the project is obsolete, the tool can still be used for other distros. In any case it might be good to learn more of the virsh command line syntax.

Some quotes below:

Quote> One of the features included with RHEL 8 Beta is the ability to manage virtual machines from the Web Console (also known as Cockpit), and the announcement that virt-manager has been deprecated. The Web Console is intended to become its replacement in a subsequent release. It is recommended that you use the Web Console as your virtual machine graphical management tool.  Brian Smith, redhat
Quote> TL;DR: I’m the primary author of virt-manager. virt-manager is deprecated in RHEL8 in favor of cockpit, but ONLY in RHEL8 and future RHEL releases. The upstream project virt-manager is still maintained and is still relevant for other distros.Cole Robinson, maintainer of virt-manager

Redhat will likely continue to add features to the cockpit virtualization plugin in the webgui and make it feature complete on par with virt-manager.