| Carl Friedrich Gauß Faculty | Department of Computer Science

Virtual Hosts

AuthorFrank Steinberg


Upon request any staff member can easly get a virtual host. You will become the formal supervisor of the host. Of course you can give additional superuser access to the installed system to your students.

The virtualization is based on x86_64 KVM. Typical VMs get ~512MB RAM, 30GB HDD, 1 vCPU, a virtual network interface bridged to the VLAN ibr-misc, and a password protected VNC console. Other configurations are possible upon request.

Most VMs are setup with a small Ubuntu LTS system with a configuration that uses the IBR LDAP and NFS infrastructure, so that all IBR users can easily login. You can also get a plain Ubuntu system or even just the VM that boots via PXE and you choose an installation from the IBR PXE menu using the VCN console.

If you want to request a VM, please send an email to Frank Steinberg. We need the following information:

  • hostname (preferably a project-related name, not too long)
  • need for a public IPv4 address and DNS domain? (otherwise a NATed private address)
  • any firewall holes (list of tuples: IP version transport protocol, port number)
  • other wishes

As with baremetal hosts: Never use a static IP configuration on your host! Always use DHCP or IPv6 SLAAC, respectively.

Some information about the new VM will be sent to you by email. The VM will have a usual LDAP host record with three additional attributes:

  • ibrLibvirtDomainXml: the KVM domain snippet, read-only, please request changed through email
  • ibrLibvirtHypervisor: the KVM hypervisor host, read-only, selected by the IBR admins
  • ibrLibvirtAutostart: controls whether the VM should be started upon hypervisor startup

Hint: If you want to connect to your VM's VNC console, read the hypervisor from ibrLibvirtHypervisor and the port and password from the <graphics> section of ibrLibvirtDomainXml using the dirac tool:

$ dirac "host myhost ; show ibrLibvirtHypervisor"
kvm1 $ dirac "host myhost ; show ibrLibvirtDomainXml" | grep graphics <graphics type='vnc' port='5937' autoport='no' listen='' passwd='PASSWORD'> </graphics>

So, we can connect our VNC client to vnc://kvm1.ibr.cs.tu-bs.de:5937 using the shown PASSWORD.

Update: You no longer need to remember the hypervisor, just the port. All VNC consoles can now be accessed through a NAT proxy, e.g. vnc://proxy.ibr.cs.tu-bs.de:5937 using the same PASSWORD.

Update2: All KVM VNC consoles are now reachable through a new NAT proxy on the well known VNC port 5900, e.g. vnc://myhost.mgmt.ibr.cs.tu-bs.de:5900 using the same PASSWORD.

You can start, shutdown, reset, reboot your VMs through the ibr-vm-control command.

Things you don't have to care about: Disk storage is based on iSCSI targets. These iSCSI devices are part of our regular backup. The infrastructure supports live migration, which is used in cases of hypervisor maintenance or to rebalance loads.

last changed 2021-03-30, 11:14 by Frank Steinberg