Entries in Xen (2)


More on the Xen Cloud Platform

The Reg's Timothy Prickett Morgan has posted Xen packages build-your-own-cloud kit and it adds some needed clarity to the upcoming Xen/Citrix announcement.

Simon Crosby's quoted as stating the goal of delivering to market a standardized stack for a cloud-based deployment of the Xen hypervisor. Prickett Morgan makes the point that it's an open source vertical platform, but clearly should not be considered a turn-key solution.

The Xen Cloud Platform does not include tools for creating, provisioning, monitoring, or managing a cloud. Rather, it is a complete infrastructure virtualization stack that companies building clouds can standardize upon.

The article goes on to point out that it's not only 'free' but hackable open source. It brings up the issue that GPL-based open source licensed code has an interesting loophole ... Since a service vendor's revised/enhanced/hacked code is not being re-distributed (but used solely for the provision of services), the license does not require the licensee to return the enhancements to the open source community. What isn't clear from the article is the licensing regime under which XCP will be offered.

Another point of clarification is the distinction Citrix is making between XCP and the Citrix Cloud Center (C3).

And this future product will be distinct from the Citrix Cloud Center (C3), formerly known as XenServer Cloud Edition, that Citrix pitched last year and tweaked when it started giving away XenServer for free this past February. ...

The Xen Cloud Platform is not C3, but it will include some storage management, chargeback, and other features that Citrix created for C3 or the Essentials for XenServer tools that are necessary for cloud providers. The cloud stack includes the Xen hypervisor, with support for either Linux or Windows instances inside of its virtual machines. The stack also includes a domain 0 Linux installer for the Xen hypervisor that is pulled right from the kernel.org site where the Linux kernel lives. ... Citrix will open source storage features it has created to link into disk arrays to do volume management, snapshotting, cloning, and such, and chargeback and other features to cope with usage tracking will be added to the stack as well by Citrix.

Of major interest is the approach to a distributed virtual switch infrastructure. The article notes that XCP will include the Open vSwitch that's available under the Apache 2 license., and is supported by the Citrix XenServer 5.5 hypervisor. This is not yet a full OSS solution, and Citrix will be under pressure to either release to open source some of their virtual switch technology, or Open vSwitch will need to light a fire.

Finally, the support of DMTF's OVF is reiterated.



Battling for the Title of Cloud VME

According to eWeek and Shannon Snowden, Citrix Systems and Xen.org will be developing a 'full-blown cloud computing platform that will rival VMware's vCloud offering.' I'm not yet sure what this means, because there are still piece parts of VMware's vCloud (particularly the details of the vCloud API) that are yet to be revealed. That said, the interview on Snowden's Virtualization Information seemed to have the right elements: portability through support of OVF (YAY!!), commitment to DMTF standards, XenMotion workload migration between datacenters and clouds, extended virtual networking infrastructure, and cloud-scale virtual storage infrastructure.

We discussed the the expected impact to Citrix and XenServer. Both Simon and Ian (Pratt) think that having a bigger footprint of XenServer is good for Citrix and ISVs in general because the (Xen Cloud Platform) XCP won’t necessarily be focused on the management layer, but the foundational components to having a stable, functioning cloud platform. After all, Citrix is already providing XenServer for free.

In fact, the orchestration and management capabilities of open source projects Eucalyptus and OpenNebula.org as well as commercial offerings from vendors and cloud providers will integrate with XCP since these projects are Xen-based already.

Simon said the plan is for Citrix Essentials to work with XCP, so this makes business sense to me. Citrix gets more XenServer in organizations that already are running Xen to power their clouds and have an opportunity to sell more Citrix Essentials.

For me, the early prize in the contest between VMware and Citrix is the cloudbursting title. This would incorporate three elements:

  1. The extended safety cordon required for expanding a private datacenter into the cloud of an IaaS, most likely based on a managed VPN like CohesiveFT's VPNCubed or Amazon's VPC 
  2. The ability to utilize hot migration -- vMotion or XenMotion -- as a basis for VM movement.
  3. A coordinated data management facility -- almost a customer directed content management network -- for identifying, moving and then utilizing data at the most appropriate location as part of the workload migration control.