Citrix Hypervisor and its new features.

[XenServer Boy]

Hello,

I have some questions:

1- Is it true that Citrix Hypervisor changed completely from Citrix XenServer? Something like two different operating systems. For example, Citrix XenServer was Windows, but Citrix Hypervisor is Linux.(It just an example, I know Dom0 is Linux).

2- Citrix Hypervisor don't use Linux as Dom0? It uses a VM?

3- The Dom0 in Citrix Hypervisor vs Citrix XenServer?

 

Thank you.

 

[Tobias Kreidl]

Same basic base (Linux), but different versions between XS and CH. Dom0 is still a Linux-based OS, and in both versions, can be considered a special VM. XS/CH are Type 1 hypervisors (bare metal). Dom0 is based on CentOS, with CH 8.2 using CentOS 7.5 as its based (with modifications to the Xen platform version).

[XenServer Boy]

Thank you.

Considered a special VM? Are you meaning a custom kernel?

[Tobias Kreidl]

Yes, it's based on Xen, which in turn is a modified version of CentOS. https://xenproject.org/

[XenServer Boy]

40 minutes ago, Tobias Kreidl said:

Yes, it's based on Xen, which in turn is a modified version of CentOS. https://xenproject.org/

 

Thanks.

Thus, it is not a Virtual Machine that launched by a hypervisor!

Is it true that CH architecture vs XS architecture? If yes, an XS administrator can't work with CH and is the architecture change important for the administration?

[Tobias Kreidl]

It's a bare metal hypervisor, with dom0 running as the base. The  architecture is just an evolution of the Xen platform over time, going from XS to CH.

[XenServer Boy]

42 minutes ago, Tobias Kreidl said:

It's a bare metal hypervisor, with dom0 running as the base. The  architecture is just an evolution of the Xen platform over time, going from XS to CH.

 

Thank you.

Google tell me:

"The control domain, also known as 'dom0', is a secure, privileged Linux Virtual Machine (VM) that runs the Citrix Hypervisor management toolstack (XAPI). The control domain provides the Citrix Hypervisor management function. It also runs the driver stack that provides user-created VMs access to physical devices."

 

The Dom0 is part of the Xen Project. When Dom0 is kind of a VM, then Xen Hypervisor running in a VM???

Is control domain part of the Xen Hypervidor?

Why PV on HVM removed?

The XS commands doesn't work in CH?

[XenServer Boy]

Any idea?

[Tobias Kreidl]

Xen hypervisor's dom0 runs on bare metal as the Xen OS (modified CentOS Linux kernel). You can consider dom0 a VM or sorts, as it spawns off all additional domu instances. You can read up about all the details at the Xen Project site, the URL of which is listed above.

[XenServer Boy]

4 hours ago, Tobias Kreidl said:

Xen hypervisor's dom0 runs on bare metal as the Xen OS (modified CentOS Linux kernel). You can consider dom0 a VM or sorts, as it spawns off all additional domu instances. You can read up about all the details at the Xen Project site, the URL of which is listed above.

 

Thank you.

As the final question, the Xen Hypervisor installed on Dom0?

[Tobias Kreidl]

They are one and the same.

[Mark Syms]

Support for PV guests is removed because they are a security nightmare, in particular since the discovery and disclosure of SPECTRE, MELTDOWN and friends. Only HVM VMs are supported now.