XenServer 6.2.0 - shedding weight to get fitter?
Citrix have released XenDesktop 7, and with it XenServer 6.2. This past week I've spent the last couple of days deafening my family as I fired up a lab server to do some of my own testing with Atlantis ILIO on this latest release. Bash scripting.. like riding a bike.. you never forget: You just sometimes end up in a heap in nettles if you've not had a proper go for a while and the whole experience can leave you invigorated, but slightly sore.
The XenServer 6.2 release is an interesting one. Citrix have traditionally been an application access company, recently there has been a move to focus effort on delivering to mobile working requirements.
Where does a hypervisor fit there?
There are a large number of feature changes in Citrix XenServer 6.2, but a lot of these changes are removals. Significantly, Citrix have moved XenServer, and XenCenter to a open source model. All features are free, as in beer. Licensing is now focused on the enterprises who require a level of support beyond relying on a pimply youth pausing his game for two minutes..
So what is new, how does it compare to 6.1, and what has ceased to be? Most importantly, where does the XenServer 6.2.0 release leave existing customers?
XenServer 6.2 - In with the New, Out with the Stuff That is Unwanted, Hard to Deliver and Maintain
So, what changed in the new release - does this release embrace the Olympian ideal of faster, higher, stronger?
Citrix XenServer 6.2 - a pre-requisite for XenDesktop 7?
While XenServer 6.2 fully supports Windows 2012 and Windows 8, you can host controller roles for XenDesktop 7 on Windows 2008R2. You could choose not to roll out Windows 8 yet. Here are the system requirements for XenDesktop 7
New and improved guest support for XenServer 6.2.0 includes:
- Microsoft Windows 8
- Microsoft Windows Server 2012
- SUSE Linux Enterprise Server (SLES) 11 SP2 (32/64-bit)
- Red Hat Enterprise Linux (RHEL) 5.8, 5.9, 6.3, 6.4 (32/64-bit)
- Oracle Enterprise Linux (OEL) 5.8, 5.9, 6.3, 6.4 (32/64-bit)
- CentOS 5.8, 5.9, 6.3, 6.4 (32/64-bit)
- Debian Wheezy (32/64-bit)
- VSS support for Windows Server 2008R2 has been improved and reintroduced
If your XD7 environment is earmarked for support of VDI into and beyond Windows 8, and you're following a Windows Server strategy that includes migration to Windows 2012, and you wanted to continue with XenServer as your hypervisor then yes, you'll need XenServer 6.2.0. This may have a different cost implication now as...
XenServer 6.2 is now available as free open source virtualization platform. This has pleased the guys at Linux.org who have upgraded their XenServer pool to XenServer 6.2.0. This new release now includes features previously only available with Enterprise/Platinum offerings. This means there is a single commercial edition of XenServer 6.2.0 licensed on a per socket basis, this commercial edition provides:
- Citrix Premier 24×7 worldwide support
- Commercially packaged and certified product
- Simplified patching and updating via XenCenter (no automated updates with the free version)
- Indemnification and license protection (yep, I understand all of the words individually too, just not all together in this context)
- Access to the Citrix My Account Portal (shrugs)
XenServer 6.2.0 now fully integrates and includes the Performance and Monitoring Supplemental Pack that was added for 6.1.0.
This means Xenserver 6.2.0 has detailed monitoring of performance metrics, including CPU, memory, disk, network, C-state/P-state information, and storage. These metrics are available on a per host and a per VM basis. These metrics are available directly through the Round Robin Database (RRD) interface, or can be accessed and viewed graphically in XenCenter.
It is also now possible to export the performance information directly as a Comma Separated Values (.csv) formatted stream enabling the use of third-party tooling, such as Splunk.
For more details refer to the Monitoring and Managing XenServer chapter in the XenServer 6.2.0 Administrator's Guide.
XenServer 6.2.0 - Scaling by Stealth?
Shortly after Microsoft released Windows 2012 HyperV v3 I attended an incredibly informative presentation from Aidan Finn on the new features in HyperV v3. I wrote about it in a series of blogs at the Virtualization Practice
Now, that was back in 2012. At the time of writing we're well into 2013: perhaps Citrix would have seen the gap between their hypervisor and Microsoft and VMware and sought to close it.
What Citrix delivered with XenServer 6.2.0 was:
- A reduction in the amount of traffic between a VM and the Control Domain (Dom0).
- Automatic scaling of Dom0 memory and vCPUs based on physical memory and CPU capacity on the host resulting in..
- VMs per host’ increase to 500 vms (Windows) and 650 (Linux) – from the previous limit of 150 VMs
How does this actually stack up as a difference between Citrix XenServer 6.1 vs Citrix XenServer 6.2?
|Capability||XenServer (6.1.0)||XenServer (6.2.0)|
|Virtual Machine Limits|
|Virtual CPUs per VM||16||16|
|Memory RAM per VM||128GB||128GB|
|Virtual Disk Images (VDI) (including CD-ROM) per Virtual Machine||7||7|
|Virtual CD-ROM drives per Virtual Machine||1||1|
|Virtual Disk Size (NFS)||2TB minus 4MB||2TB minus 4MB|
|Virtual Disk Size (LVM)||2TB minus 4MB||2TB minus 4MB|
|Virtual NICs per Virtual Machine||7||7|
|Logical processors per host||160||160|
|Virtual CPUs per host||900||4000 (Windows VMs) / 12000 Linux (VMs)|
|Concurrent protected VMs per host with HA enabled||60||500|
|Concurrent VMs per host||150||500 (Windows VMs) / 650 Linux (VMs)|
|RAM per host||1TB||1TB|
|Concurrent active virtual discs per host||512||512|
|Physical NICs per host||16||16|
|Physical NICs per network bond||4||4|
|Virtual NICs per host||512||512|
|VLANs per host||800||800|
|VLANs per physical NIC||####||1019|
|GPUs Per Host||4||12|
|Resource Pool Limits|
|Hosts per resource pool||16||16|
Gone to the Great Hypervisor Functionality Code Bucket in the Sky are:
- Workload Balancing and associated functionality (e.g. power-consumption based consolidation - sounded a good idea, but likely rarely used: especially as the optimum performance came through turning all the dials to 10)
- XenServer plug-in for Microsoft’s System Center Operations Manager
- Virtual Machine Protection and Recovery (VMPR)
- Web Self Service - Citrix recommend that CloudPlatform offers the superior solution to delegated admin requirements and VM controls. If you don't have the requirements for a full orchestration solution the suggestion is to take a look at xvpsource.org, an open source alternative.
- XenConvert (P2V)
- Microsoft System Center Virtual Machine Manager (SCVMM) support:
- Integrated StorageLink (iSL)
- Distributed Virtual Switch (vSwitch) Controller (DVSC). The Open vSwitch remains fully supported: if you still trust it, as many found issues with the 6.1 release.
Citrix XenServer 6.2.0 - Does shedding a few pounds make it a more mobile and healthier?
XenServer 6.2.0 offers increased density options, key for VDI (and despite the proliferation of web applications, desktop application support is still going to be key for the next at least the next 2 years). Windows 2012, Windows 8 support is now here now, all you need is Windows 8 to be re-convinced that it isn't just being used on a touch screen tablet.
Still, unlike a traditional release, XenServer 6.2.0 is leaner than previous versions and perhaps fitter for the tasks ahead. Finally it has been accepted XenServer won't match the vSphere (too embedded) and Hyper-V (too readily seen as "free", and soon to be emdedded). Despite both VMWare and Microsoft being key partners, Citrix have to keep their options open to be able to support a hypervisor that can help facilitate use cases for their key market of enabling mobility, and to host their CloudPlatform suite. The difficulty is that they have chosen to do this by playing the "opensource" card - which will turn off many enterprises: a pity, as Citrix will still offer paid support for XenServer - it is still as viable enterprise product.
Citrix want to provide an end-to-end capability that delivers hybrid cloud services. While the marketing focus is on enterprise mobility (XenMobile) and application and desktop delivery (e.g. XenDesktop 7), their jewel is the optimization of networking for those services with Netscaler. There will likely be increasing growth of OS independent collaborative applications (Sharefile, Podio, GoTo-XYZ) and CloudBridge. All these technologies sit on a hypervisor, but the hypervisor market is increasingly commoditised. If Citrix can better highlight support a stable hypervisor that continues to support current drivers - why push resource and effort into delivering enterprise features it will unlikely need?
And so we have XenServer 6.2.0 - not the end of a chapter, but the beginning of a new one.