New email from Microsoft promoting the upcoming Management Summit may have inadvertently revealed roadmap information for a future release of the Surface tablet. Perhaps in response to the poor battery life highlighted by critics, we may soon see a resurrected version of Windows NT running on this tardy entry into the competitive tablet market.
What do you think — is Windows NT an iPad killer?
Tags: Microsoft
Slow news day at ComputerWeekly.com — at least based on the reruns they are playing of the Menzies Aviation Hyper-V case study. One thing that really stands out in that article is the apparent lack of understanding on the part of the IT staff at Menzies when it comes to high availability and shared storage:
One Hyper-V 3.0 feature is called Shared-nothing live migration. It allows administrators to migrate a virtual machine (VM) from one physical server with direct attached storage to another physical server with direct attached server.
It requires no clustering or shared storage between both servers as just a small connection such as a Gigabit Ethernet (GbE) cable will suffice resulting in zero down time.
For the cargo company that operates in 180 airports around the world, security and zero downtime were key criteria.
Both Hyper-V and vSphere allow administrators to place virtual disks on local storage or on a shared SAN. VMs using local disks are essentially pinned to one physical host and cannot be migrated to accommodate events like shifting resource requirements or host maintenance. Enter “shared-nothing live migration” — an interesting new enhancement found in the most recent releases from both Microsoft and VMware which allows administrators to move a VM and storage in a single operation.
Just the thing for environments that require zero downtime, right? Not exactly.
Important workloads with high uptime requirements need to be protected from physical host failures. HA is responsible for restarting failed VMs on surviving hosts, but this is only effective when VM disks are still available — on shared storage. Virtual disks residing on local storage will remain offline until the physical host is brought back online.
It’s that simple. Being able to migrate a VM and storage together is a feature with interesting use cases — none of which have to do with application availability and local storage.
For those interested in all the gory details, check out this excellent technical paper on VMware vSphere 5.1 vMotion.
Tags: high availability, Hyper-V, live migration, vSphere
Perhaps you are a technology professional who has not had a chance to serve on the front lines of virtualization but would like to know what the key considerations are when planning and implementing the industry-leading vSphere virtual infrastructure solution. Maybe you have been stuck in a position trudging along with a competing virtualization platform that is based on a legacy general-purpose operating system, looking for a great primer to quickly get up to speed on VMware vSphere concepts and terminology — and a chance to see how straightforward things are when purpose built for cloud infrastructure.
I recently had the opportunity to review the new book on VMware vSphere 5 by Eric Maillé and René-François Mennecier entitled Building a Virtual Datacenter. It covers a lot of ground and would be very good resource for those ramping up on VMware technologies. With a foreword by Chad Sakac, you know it’s legit.
Most hypervisors now have, or will have, support for SR-IOV networking — VMware introduced support in vSphere 5.1. One of the downsides of using this technology, which provides direct network access to a virtual machine, is that it hinders mobility — vMotion is no longer possible. The new Hyper-V works around this limitation by temporarily routing I/O through a virtual switch during live migration. Ingenious, no?
Over three years ago, VMware and partners demonstrated a solution to the SR-IOV/vMotion issue — by temporarily switching from passthrough to emulation mode it was possible to migrate a VM from one host to another. This innovation can be seen in the following demonstration:
Now, you may be asking why VMware never shipped this feature if it existed over three years ago. I’m not privvy to any specific details on the topic, but it would be sensible to say that decisions to release features are made based on priorities such as customer value. Although hardware with SR-IOV support is now becoming widely available, the customer use cases are still very much at the edges. Consider this: if a workload is so latency-sensitive that SR-IOV is truly required, how acceptable is it to impact service levels while I/O is rerouted during this migration period?
While this feature isn’t part of a shipping product from VMware, I’d argue that vSphere had it before Hyper-V for all intents and purposes. Especially considering the weight Microsoft gives to the capabilities of their pre-release software.
Happy New Year!
Tags: ESX, live migration, VMotion
At the recent VMworld 2012 event, VMware announced the elimination of vRAM licensing for vSphere, moving back to the per-socket model (and eliminating core restrictions in the process).
There seems to be some confusion as to whether or not this applies to vSphere 5.0 or if the move was a sinister plan to force all customers to upgrade to the latest release, recently-announced version 5.1.
It’s simple: there is no more vRAM entitlement in any version of vSphere — not in 5.1 and not in 5.0.
In the VMware vSphere 5 Licensing, Pricing, and Packaging document, the FAQ section makes it very clear:
Q: Does the new VMware vSphere 5 licensing model – per-CPU
without limitation on the number of VMs, cores or amount
of physical RAM – apply to both vSphere 5.0 and vSphere 5.1?A: Yes. The VMware vSphere 5 licensing model applies to both
vSphere 5.0 and 5.1 customers.
VMware vSphere 5.1 is an awesome product, but you are not forced to immediately upgrade in order to enjoy the benefits of this recent change.
The views and opinions published on this site belong to Eric Gray and are not approved or endorsed by his employer, VMware, Inc.
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