|Well the Brownbag discussion topic has been decided and we even have a guest speaker.|
I am delighted to anounce that Scott Vessey of Global Knowledge will be onboard to discuss VMware certifications. Now as with the best laid plans of mice and men, we seem to have a timing FUBAR.
I must remember that the first Thursday of the month is not a good time for Brownbags as half of the Virtualisation peeps in London are leathered.
|So to sum up :|
|7pm on the 7th of July.|
|Use the link below to register.|
I have to admit that this one slipped under my radar, but apparently this an offer from the VMUG to provide cheaper access to certain VMware products. so the first question is what is the VMUG? it is VMware’s independent, and global organization that supports the local VMware User Groups. it was re-organised in mid 2010 to become a more customer-led organisation and appointed a number of Local VMUG leaders to a council to promote their message which is to maximize their members’ use of VMware and partner solutions through knowledge sharing, training, collaboration, and events
WOW you say so how can join, Now membership to VMUG is free of charge (you can sign-up here). there are local VMUG’s that regularly hold meetings, for example the UK as the London VMUG, the Northern VMUG, and the Scottish VMUG. However the global VMUG introduced what it has called the ‘Advantage’ programme; this is a paid-for addition to your membership which gives you an opportunity to obtain certain VMware products and education offerings at a discounted price.
The full benefits are listed here (and include a 20% discount on instructor led training;30% discount on VMware Fusion and VMware Workstation; and 1 Years FREE subscription to all VMware eLearning Courses (worth $750)!
Now as an incentive, membership prices have been discounted until May 21st, 2011:
Individual package: $170
Corporate package with 2 users: $165 per user
Corporate package with 3+ users: $160 per user
Standard VMUG Advantage Pricing (after May 21st) will be:
Individual package: $200
Corporate package with 2 users: $180 per user
Corporate package with 3 – 5 users: $170 per user
Corporate package with 6+: $160 per user
If this interests you, you can subscribe here.
Although this is a nice addition to what the VMUG’s offer it is still not TechNet, now many people may not realise this but VMware used to have a similar offering to TechNet called the VMTN subscription for £199 a year, this product went end of life with the release of VI3. My personal wish is that this be returned, and made available in a similar fashion to Microsoft’s TechNet.
What Is It?
VMotion is arguably VMware’s “killer app” – the feature that gave VMware’s hypervisor product a USP edge over its competition. It enables an ESX host to transfer a running virtual machine over to a different ESX host without incurring downtime.
When a VMware administrator initiates a VMotion migration the memory state of the chosen virtual machine is copied via a dedicated network link from the source host to target host; when completed the target host registers the guest machine, attaches the virtual NICs to its own vSwitch(es) and takes control of the guest.
The handover happens so smoothly that network connections are maintained, rendering the process invisible to users, who at worst see the server pause for a second or two.
This feature effectively separates the physical hardware from the operating system, resulting in major benefits to business :-
- A running virtual machine is no longer dependent on a single piece of hardware, reducing the risk of service outages should a hardware failure occur.
- There is no need to perform planned hardware maintenance outside of working hours, reducing costs and improving responsiveness.
- Workloads can be juggled across servers to best utilise the resources available: if an ESX host gets busy, guests can be moved off to a less busy hosts until balance is restored, improving efficiency.
What Do I Need to Deploy It?
Two ESXi/ESX hosts with compatible CPUs: The target host must support the same processor features as the source host, otherwise the virtual guest could issue a command that the host cannot understand and result in the guest crashing. For example you cannot migrate from an Intel server to an AMD server. There are VMotion Compatibility Guides that group compatible server types together (see links below).
New to vSphere, Enhanced VMotion Compatibility (EVC) can be enabled on a cluster to improve compatibility by checking with the hosts and calculating a CPU “mask” – a list of features supported by all hosts in the cluster. As a last resort, and unsupported by VMware, a custom CPU mask can be defined manually (see the KB article linked to below for more details).
VMware Licensing: Both hosts must be licensed with either Essentials+, Advanced, Enterprise or Enterprise+.
vCenter Server: Source and target hosts must be managed by the same vCenter server (or linked vCenters), as migrations are initiated from the vCenter server, either from vSphere Client or the Move-VM cmdlet in Powershell.
VMotion Network: A vmkernel interface (with an IP address separate from the Service Console or Management interface) must exist on both hosts for the express purpose of VMotion comms.
Because of the time-critical nature of the migration it must be a fast link (bandwidth >622Mbps, latency <5ms round trip) so Gigabit is required. For resilience the vSwitch should have two or more NICs from different physical switches.
Also note that VMotion data is NOT encrypted — and therefore insecure — so it is recommended that a dedicated VLAN and IP range be allocated for the VMotion interface.
Finally, if the VMotion network traverses a firewall then tcp port 8000 needs opening up.
Shared Storage: The underlying files that make up the guest virtual machine must be accessible by both source and target host.
Is VMotion Safe?
Generally VMotion is very safe, with any errors reported in the Task Pane and the migration aborted. There are a few circumstances where VMotion isn’t possible :-
- If the VM has a resource attached that is not available on the target – for example if a mapped CD ISO is stored on the source host’s local datastore. (Storing ISOs on a shared LUN avoids this issue.)
- If the VM has a physical SCSI controller attached, for example on virtual Microsoft Cluster nodes, or has a VMDirectPath device attached (which gives the guest direct access to a PCI device on the host).
- Where the target host has insufficient resources to honour the guest’s requirements AND strict admission controls are in place for the cluster.
There are two priorities of VMotion available – High and Low. This is about protecting performance of the guest, not of the migration. A High Priority migration reserves sufficient CPU cycles on the target host to satisfy the guest’s requirements, otherwise it will abort the migration. A Low Priority migration will go ahead regardless of target host CPU utilisation.
As VMotion transfers the memory state of the guest to the target host, a guest with 64Gb of RAM will take significantly longer to migrate than a guest with 1Gb of RAM.
It is possible to run 4 concurrent VMotions on vSphere 4.1 hosts with Gigabit networking – if you’re lucky enough to have deployed 10Gb networking you can run up to 8 VMotions at the same time.
How Does VMotion Tie In With Other Features?
Putting a host into Maintenance Mode initiates the VMotioning of all running guests off that host.
DRS (Distributed Resource Scheduler) provides automated balancing of resources across all hosts in a cluster. When enabled, vCenter analyses host utilisation every 5 minutes, and if a host is deemed significantly busier than the rest it will initiate VMotions of one or more guests off that host to lighten the load.
HA (High Availability) is a technology that monitors host availability, responding to failures to ensure a failed host’s virtual machines are brought online quickly on a working host. It doesn’t use VMotion to achieve this.
So What Is Storage VMotion?
Storage VMotion is a separate feature for Enterprise or Enterprise+ hosts that provides the ability to move a running guest’s data files from one datastore to another. This feature is fantastic for SAN migrations or maintenance work. Migrations can also convert VMDK files between Thin and Thick formats.
One word of caution: Storage VMotion of guests with RDM (Raw Disk Mapping) disks attached will by default convert the RDMs into VMDK files! If RDMs are deployed, use the Advanced mode in the migration wizard.
Storage VMotion won’t work for guests with snapshots in place, or if any disks are non-persistent.
One final tip: If taking advantage of Storage VMotion it is worth checking whether your SAN is VAAI capable, in which case the vCenter can talk with the SAN to offload some disk actions such as this, improving performance.
Where Do I Go From Here?
Introduction to VMotion: http://www.vmware.com/products/vmotion/features.html
Configuring VMotion Networking: http://www.youtube.com/watch?v=VaGtMtYA6H0
VMotion Compatibility Guide for Intel processors:
VMotion Compatibility Guide for AMD processors:
Modifying the CPU mask:
This is late, because the fact is that I have not ‘just’ sat the workshop, it was almost a month ago. It is funny how time gets away with you when you are enjoying yourself :S Simon Bodecott know what I am talking about LOL. But seriously I digress, on with the subject at hand.
As I have said, I recently attended the VMware vSphere Design Workshop. the course was provided by Global Knowledge at their Wakefield site. Yes I know ‘Yorkshire’. well I made sure that I all my inoculations were up to date before I travelled over the Hill into forbidden territory (this is a UK joke – that has gone on for centuries)
So what did I think of the course? on the whole it was worth while, the instructor, well that is not really the term to use for this course, Facilitator would be a better term, as the course format is more of a here are the principles now discuss this situation and provide a design, than the traditional Death by Powerpoint.
Our Facilitator Chris Culpin was one of those VCI’s that actually has a real job too, 😉 just pulling your leg Scott. LOL. what I mean by that is that he also did Consultancy as well as presenting training courses, what this gave to the group was an instructor with real world experience of the issues and design decisions that you as a VMware designer would come across.
With all that said, the course could have been a day or two longer. we did not have the time to really deep dive into the reason for making a particular design decision. but conversely if we had not had such a vocal group of delegates the course could have been a disaster and I think that really sums up the course. this is one of those rare courses where the instructor is not the important one. it is the delegates.
They make or brake the course. if you get a bunch of shrinking violets who will not interact, you will not get any benefit out it. you really need to be vocal and discuss your decisions and get a bit of a technical argument going, this will push your boundaries.
So was this beneficial to me? Yes I think it was. It gets you thinking about how your decisions affect the overall design. As training for the vCAP DCD yes it is useful, however personally I think it will be more useful for it if I ever get to sit a VCDX defense.
I recently took delivery of the latest Trainsignal DVD’s yep that’s right the the VMware vSphere Troubleshooting Training ones. once again the Trainsignal team have outdone themselves and a special thanks should go to David M Davis.
The videos are succinct and to the point, David gets to the root of the matter during his lessons, and yes I do mean lessons. Most people can and will learn something off this set of DVD’s. The lesson plans are easy to follow and the format allows for easy review.
They should be a standard part of anybodies armoury if they are attempting the vCAP DCA exam
Vyatta are slowly becoming one of my favourite networking start-ups…
Not only do they have a first class Router and Firewall/VPN product – boasting higher performance than Cisco – that they give to the community (here), they now offer free training at the Vyatta University! Specifically a new free video course related to Routing and Security in VMware and Citrix
Vyatta are slowly becoming one of my favourite networking start-ups…
Not only do they have a first class Router and Firewall/VPN product – boasting higher performance than Cisco – that they give to the community (here), they now offer free training at the Vyatta University!
Back in March, Vyatta Core reached v6.0 providing additional features that make their product more attractive to the enterprise.
- Netflow / sFlow logging and analysis
- 802.11 wireless LAN – (access point + base station)
- Binary image installation – (version mgmt)
- IPv6 readiness (core routing and firewall)
- Firewall enhancements
- IPv6 firewall
- P2P firewall
- time-based and zone-based firewall rules
- QoS Enhancements
You may have read my post on using Vyatta as a Router-in-a-box for VMware and Citrix…
Seeing how this is such an attractive use case for this product, Vyatta have published a course detailing installation, verification and basic configuration of Vyatta OVF and XVA virtual appliances for adding routing & security to VMware ESX and XenServer environments.
I very much like Vyatta’s approach, offering the Core Edition to the community with support subscription available as an uplift and it is even more refreshing to see Training following in the footsteps.
A strong community and easy access to resources satisfies engineers and will yield a greater amount of knowledgeable/certified individuals should Vyatta choose to go down this route.
Perhaps more Networking vendors could learn from this…
Train Signal, who produced the popular ‘VMware vSphere’ and ‘Hyper-V’ training videos have just released a new addition to the VMware vSphere suite of training products called ‘VMware vSphere Pro Series Vol. 1’.
Train Signal, who produced the popular ‘VMware vSphere’ and ‘Hyper-V’ training videos have just released a new addition to the VMware vSphere suite of training products called ‘VMware vSphere Pro Series Vol. 1’. Continue reading “TrainSignal release a new Training video.”