viktorious.nl - Virtualization & Cloud Management

Software Licensing – A limiting factor on cloud workload mobility?

viktorious — Wed, 22 May 2013 21:20:29 +0000

Private, public and hybrid IaaS cloud offers you new, flexible deployment options for your virtual machines. By utilizing a central catalog containing your templates, you can deploy virtual machines with a simple mouse click. If your using some kind of catalog synchronization tool (VMware offers Cloud Connector for this), you can synchronize templates throughout all different on- and off-premises clouds you're using. Another nice feature when talking about private, public and hybrid cloud is workload mobility. In a cloud scenario this means you can move your workload (virtual machines) from one cloud to another cloud, from private to public, from public back to private and also between public clouds. When you choose to run DTA workloads in a public cloud (and not in your on-premises environment), workload mobility enables you to move or copy a workload from your on-premises virtual infrastructure/cloud to the public cloud provider. Another example is when you want to switch from public cloud provider, part of your exit strategy is to move the workload from one cloud provider to the other. For VMware Cloud Connector is the workload mobility tool, Microsoft has App Controller in place for this.

Workload mobility and Microsoft licensing

Let's look at these use-cases/scenarios from a Microsoft Windows OS licensing perspective (there's some information about Microsoft application licensing at the end of the article). As you might know, in a virtualized environment Microsoft Windows licensing is linked to your physical servers:

One standard license allows you to run 1 virtual machine or so called Operating System Environment (OSE) per physical server;
One enterprise license allows you to run 4 virtual machines (OSE) per physical server;
A datacenter license allows you to run unlimited virtual machines (OSE) but is payed per CPU socket and not per server.

In a public cloud scenario you don't know which physical server is running your virtual machine, which makes it impossible to link these licenses to particular physical servers. Actually Microsoft won't allow you to use your own licenses in a public cloud scenario, you have to buy the licenses from your cloud provider under the SPLA (Service Provider License Agreement) model. This means your paying a license fee to your cloud provider and your using their agreement with Microsoft for your virtual machines. Let's see what Amazon Web Services (AWS) is telling us when licensing Windows servers running in their EC2 cloud:

Q. Can I use my existing Windows Server license with EC2? No. Microsoft Windows Server licensing does not currently support using your existing Windows license in Amazon EC2 or any other cloud environment. We encourage you to work with your Microsoft account representative to understand licensing options. Source: http://aws.amazon.com/ec2/faqs/

Hmm, if I am not allowed to use my own licenses can I use my own images or do I have to use the images supplied by Amazon? If this is this case, this puts big limitations on the concept of workload mobility. Fortunately there's some information about this on the AWS website:

When you import your on-premise Microsoft Windows VM images into Amazon EC2, AWS will provide the appropriate Microsoft Windows Server license key for your imported instance. Hourly EC2 instance charges cover the Microsoft Windows software and underlying hardware resources. Your on-premise Microsoft Windows license key will not be used by EC2 and you are free to reuse it for other Microsoft Windows VM images within your on-premise environment. If you export an Amazon EC2 instance, access to the Microsoft Windows Server license key for that instance is no longer available through AWS. You will need to reactivate and specify a new license key for the exported VM image after it is launched in your on-premise virtualization platform. Source: http://aws.amazon.com/ec2/vmimport/

So, yes you can move a workload but you're required to change licensing key and use the Amazon supplied SPLA license key. The original becomes available and can be reused for another on-premises workload. At this point you might think that Microsoft licensing is limiting these options from a competitive standpoint? Well, that's certainly not the case. For Microsoft's own Azure cloud a kind of the same statement is published:

If I upload my on-premises Windows Server image to Windows Azure, do I need to provide my license keys? No. Microsoft provides the Windows Server license keys for any running instances. If I download my Windows Server image running on Windows Azure to on-premises, is the license provided in Windows Azure transferrable to on-premises? No. If you download your Windows Server image running on Windows Azure to on-premises, you will then be required to supply a license for the image. Source: http://www.windowsazure.com/en-us/pricing/details/virtual-machines/

I've been looking around to find more information on this for VMware vCloud IaaS providers, unfortunately I didn't find a clear statement. I have found the following information in the VMware vCloud Hybrid Service Product FAQ:

Can I bring my existing virtual machines and licensed applications into vCloud Hybrid Service? Absolutely. One of the key benefits of the hybrid cloud is the ability to bring your existing virtual machines and networking architecture into the hybrid cloud. In addition, the platform supports more than 3,700 applications from more than 2,200 technology partners. vCloud Hybrid Service includes an operating system and application catalog as part of the service, which makes commonly used workloads available. As long as you maintain license compliance with your existing software vendor, you can bring your licensed software into the cloud without problems. Source: http://www.vmware.com/files/pdf/vchs/vCloud-Hybrid-Service-FAQ.pdf

And that is exactly the caveat...(at least) Microsoft doesn't support Cloud Mobility (that's what it's called) for the Windows Operating System; thus you're not allowed to transfer your Windows OS license from private to public cloud.

Microsoft Server Applications and Workload Mobility

Although workload mobility is not available for the Windows OS, Microsoft supplies you with mobility options for some of their server applications a.i. Exchange, SQL Server and Sharepoint (the full list is on the Microsoft website). This means you're allowed to install these selected applications on the SPLA license Windows OS in a public scenario (and transfer the license to the public cloud). Full details on the Cloud Mobility licensing option for applications is available on the Microsoft website: "License mobility through software assurance". Software Assurance is key in this case and you have to take a few additional steps for compliancy. On top of this your Cloud Provider should be an Authorized License Mobility Partner and of course must be an SPLA. I hope this article gave you some information on licensing Microsoft software in a cloud scenario. Always work with your Microsoft account representative to understand licensing options. This article is just based on information publicly available on the internet.

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VMware to announce Hybrid vCloud Service availability

viktorious — Tue, 21 May 2013 05:59:21 +0000

I just popped into this webpage which I wanted to share: VMware will announce its hybrid vCloud service on May 21 10:00 PDT. Pat Gelsinger (VMware's CEO) and Bill Fathers (General Manager Hybrid Cloud Services) will host an on-line session which you attend for free. More information and registration for this session are available here. Do you want to test VMware's Hybrid Cloud? There's already a Hybrid Cloud evaluation offering on-line, allowing you to test VMware's Hybrid 90 days for free. Want to know more? The evaluation is available here.

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Virtualization & Cloud Event Agenda for Benelux

viktorious — Wed, 15 May 2013 11:24:25 +0000

I've created a short agenda containing some good Virtualization & Cloud events that are coming up! VMware's Forum is traveling around the world, VMUG Belgium is hosting another meeting and Nutanix invites you for the grand premiere of the latest Star Trek movie "Star Trek into Darkness". Here we go:

VMware Forum 2013 - At VMware Forum 2013, VMware will bring together everyone who has a professional stake in driving cloud innovation, growth and adoption. Through inspirational keynotes and technology deep dives, IT professionals will learn about the latest cloud, virtualization and mobility technologies and strategies, as well as best practice in how to drive their IT organisation towards a Software Defined Data Center and a truly flexible Multi-Device Workspace. Netherlands (Den Bosch): June 4th 2013. For Belgium the events is taking place today (May 15 2013). Other locations available on the VMware Forum 2013 website.
VMUG Belgium Meeting - The Belgian VMUG will host its next meeting on May 29 at Brussels. Attendance is free, but you have to register in advance. VMUG Belgium is hosting full conference days for a while now, and they're really of great value. If you haven't attend before...give the event a try! More information here.
Nutanix Movie Event - Nutanix is inviting you now to join for the premier of the latest Star Trek movie: Star Trek into Darkness. Before viewing the film, attendees will learn about the next-generation computing platform from Nutanix that is transforming the enterprise datacenter. This event is by invitation only, you have to fill out a form to request admission to this event. For Amsterdam the event takes place on June 6. For registration and other world wide locations visit the Nutanix website.

Don't forget to come by at the Genius bar at VMware Forum 2013 The Netherlands. Together with some good virtualization friends we will be ready to answer all your questions. More information about the Genius bar here.

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6 steps to a successful Disaster Recovery plan

viktorious — Tue, 14 May 2013 14:57:00 +0000

Recently I've been working on various disaster recovery (DR) projects, most of them having VMware Site Recovery Manager involved. Although SRM can be an important part of a DR project, Site Recovery Manager isn't Disaster Recovery. SRM is tool which features some great DR automation, DR testing and auditing features, but it all starts with determining the exact requirements for Disaster Recovery & Business Continuity for your organization. These requirements define what DR scenario best fits the situation. You might want to use SRM, but an active/failover site configuration can also be good option depending on the exact requirements. Also take a vSphere Metro Storage Cluster (vMSC) configuration in account; this is another option which lets you streched you storage solution over two or more datacenters. Don't forget some applications offer high availability/disaster recovery options right out-of-the-box. The question is how to determine what scenario will suit your organization...

6 steps to a successful Disaster Recovery plan

In my presentation about Disaster Recovery at the Dutch VMUG Event 2012 I presented 6 steps which can help in organizing your thoughts about DR:

Business Continuity Policy - What Business Continuity (BC) policy is valid for your organization? Are there any law and regulation requirements? What goals does your organization want to achieve regarding BC?
Business Impact Analysis - What critical functions are present in your organization? Identify critical processes and resources and their interrelations. Determine Maximum Tolerable Downtime (MTD), Recovery Point Objective (RPO) and Recovery Time Objective (RTO) for IT services and applications.
Develop a recovery strategy - Discuss a global DR scenario for your environment. Which technologies do you want to have in place? What geographical separation is required? How is data availability at the failover site guaranteed?
Develop a Disaster Recovery plan - Get the necessary procedures in place, which recovery solutions are you using and which roles and tasks should be defined within the organization.
Test your DR plan - Don't forget! Writing your BC/DR plan is a first step, you should definitely test it to verify everything is working as designed. Make improvements to your plan based on the testing results. You should test your plan at least once a year, but maybe more often.
Maintain your plan - And the last step? Well, when your BC/DR plan is ready and you everything in place, you shouldn't forget to maintain the plan. You organization might change and thus the critical processes which are part of the BC/DR plan. An application might be upgraded or a new IT service in your organization should be part of the plan. Bottom line...your plan is a 'living' plan and should be maintained.

Don't forget to also think about preventive controls to mitigate the risk of a disaster. E.g. UPSes or emergency power system can reduce the risk of power outage. As you can see technology, wether it is SRM, vMSC or something else, is just supportive to BC/DR. In an ideal world (and yes, I know...the reality is sometimes different) BC/DR should be iniated by the business with technology supporting the whole thing. I hope this will help you to think about BC/DR. I would be happy to discuss any questions you might have regarding DR, you contact me by e-mail at viktor at viktorious.nl.

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The vSphere 5.1 Web Client – A walkthrough (part 2)

viktorious — Wed, 08 May 2013 15:25:15 +0000

A couple of months ago I wrote an article about the vSphere 5.1 web client, which is a full featured web based management client for your vSphere environment. The web client is desginated to replace the Windows vSphere Client in the future. You probably already noticed that certain configuration options are only available in vSphere web client. I thought it would be a good idea to summarize the most important options here as a continuation on the previous article. So, here we go:

Single Sign On - The single sign on feature of vSphere 5.1 can only be configured through the web-client. Single sign on the centralized authentication\authorization solution for vSphere 5.1, vCloud Director, vShield, etc.
No shared storage vMotion - The option to vMotion a virtual machine without shared storage is only available in the web client through the "migrate" option. The Windows vSphere Client will display the progress of the process tough.
LACP nic teaming - LACP nic teaming (so not the IP based teaming option) can only be configured through the web client. On top of this vDS health check, export/restore configuration and diagram filtering can only be executed from the web client.
vSphere replication - vSphere Replication enables you to replicate virtual machines to another host/cluster. You will need to deploy a vSphere replication vApp before you can use this feature. Enabling virtual machines for vSphere replication is the next step and completed in the vSphere web client.
Integration with vCenter Operations - Although the Windows vSphere Client lets you display the vCenter Operations interface, the vSphere Web Client allows you to click open an object with "Open in vCenter Operations". This will directly display the object in the correct vCenter Operations context.

On top of this some plugins only work in conjunction with the vSphere Web Client, such as:

Integration with vCenter Orchestrator (vCO), vCO workflows are displayed in the vSphere webclient and can also be executed from the webclient.
The Virtual Infrastructure Navigator (VIN) is tightly integrated with the vSphere Web Client showing the inter-application relations.

Also note that some plugins only work in the "old" vSphere Windows client. VMware Update Manager can only be managed through the Windows client and also for Site Recovery Manager you will need the Windows client. Don't forget to check if your 3rd party plugins are vSphere webclient compatible; if this is not the case you will need the vSphere Windows client here as well. Also check this article Justin King and don't forget to read part 1 of this walkthrough.

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What is VMTurbo Operations Manager?

viktorious — Wed, 08 May 2013 06:33:09 +0000

I while ago I've been playing around with VMTurbo Operations Manager, a solution for virtualization management and datacenter control. VMTurbo offers insight information on how your virtual infrastructure is performing, and lets you prevent problems by pro-actively managing your virtual machines. VMTurbo Operations Manager is available for a wide variety of virtualization & cloud platforms, including VMware vSphere, Microsoft Hyper-V, Citrix XenServer and Red Hat KVM. VMTurbo comes as a virtual appliance (for the platform you prefer) which is available for download, deployment is very easy. Notice the system requirements for the vApp: VMTurbo requires 16 GB of RAM and 2-4 vCPU's...although a smaller configuration (for lab usage) will work. After deploying the vApp you have to complete a few configuration steps:

Set the IP configuration for the virtual appliance; typically by logging in to the appliance with username ipsetup and password ipsetup.
Connect the VMTurbo to your favorite virtualization platform.

Connecting to a virtualization platform

After you've completed IP configuration, open the VMTurbo application in a webbrowser. It's a flash application, so you'll need flash installed. First you have to select which version of VMTurbo you want to use:

Free Community edition - The Community Edition of VMTurbo Operations Manager product is provided at no cost and with no infrastructure limitations. It provides basic real-time visibility across all virtualized hosts and virtual machines, helping you identify issues and understand the breadth of problems in your environment. The product also provides a set of infrastructure reports that can be used to show historical performance across your virtual datacenter. You will need a free key which can be requested online.
Enterprise edition - This edition includes the Economic Scheduling Engine functionality which drives intelligent and automated decision-making for your virtual environment. This edition prevents performance issues, tune the environment to perform optimally, ensure business critical applications have the resources they require, intelligently plan for future capacity and hardware changes – all without manual intervention. VMTurbo Operations Manager is for on-premise datacenters without multi-tenancy or cloud architecture requirements. Enterprise edition is available as 30 day trial, or as a payed version.
Cloud edition - VMTurbo Operations Manager Cluod Edition integrates directly into VMware vCloud Director and the Open Source CloudStack offering to enable enterprise private cloud builders and cloud service providers to build and manage cloud infrastructures. The product understands priority and makes resource allocation decision across Organizational and Provider Virtual Datacenters in a vCloud Director deployment, helping you to tier and assure service across a multi-tenant environment. Cloud edtion is available as a 30 day trial, or as a payed version.

(description of the editions taken from the VMTurbo website) After you have selected a version you can link a virtualization or cloud platform to VMTurbo. I would advise to create a seperate VMTurbo user to connect to vSphere (or any of the other platforms):

A user with read only + browse datastore privileges for the monitoring feature;
A user with administrator privileges to enable the execution of real time recommendations. This is not required for the Community Edition because this version doesn't include the recommendation feature.

After a successful connection, you're ready to rock 'n roll. I will discuss the free community edition, which focuses on monitoring and reporting. The full featured enterprise edition includes some intelligent and automated decision making, which I will discuss in a future article. In the community edition you have the home and inventory tab available in the interface. You also have a (limited) set of reports available which can be accessed through the reports option. Reports included are (i.a.):

Storage Top Disk Consumption
Storage Top Snapshot Consumption
VM Rightsizing Recommendations
VM Over/Under Provisioning 90 Days
Utilization Levels by Hour
Etc.

It takes at least one day before the reports are available, because they're created in a batch job that runs every day/week/month. The home and inventory tab display actual live data; there some graphs/gauges show information after a batch job has run. VMTurbo Operations Manager of course monitors CPU, memory, network and disk. VMTurbo also show a figure called the Utilization Index (UI) which is explained as: "A measure of the risk to Quality of Service (QoS) that a consumer will experience. The higher the UI on a provider, the more risk to QoS for any consumer of that provider’s services. For example, a physical machine provides host services to one or more VMs. The higher the UI on the provider, the more likely it is that the VMs will experience QoS degradation. Note that for optimal operation, the UI on a provider should not go into double digits. In the above example, if the PM has a UI of 16 or more, the VMs are very likely to suffer QoS degradation." Apart from performance data, VMTurbo Operation Manager also displays capacity information; try the "Project Cluster Resources" and the "Monthly Summary" for example. The latter dashboard offers some information on the growth of your virtual environment. The inventory option in VMTurbo is pretty extensive. You can get insight information on the various objects in your vSphere inventory. Select the inventory object or a object group, and relevant information is shown on the right side of the screen. For example; selecting the storage object will offer information on used capacity, iops and latency. By selecting one of the available storage volumes, you will actually drill down to this particular volume. The datacenter option will show you information on the datacenter as a whole, nice to know how many GB's of RAM, Ghz of CPU's and disk storage is used. Just play around in the interface and you will find the dashboard that are relevant for you. I hope this article gives you an impression of VMTurbo Operations Manager. You can download the free community edition (or any of the other versions) here. Also check these other "What is?" articles on viktorious.nl:

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vSphere 5.1 & Hyper-V 2012 memory concepts explained and compared

viktorious — Thu, 02 May 2013 14:57:52 +0000

While searching for additional info on the Dynamic Memory feature of Hyper-V 2012, I bumped into various articles which discuss this improved Hyper-V v3 feature. Dan Stolts of the IT Pro Guru Blog published a good article on the concept of dynamic memory and how Hyper V leverages this technique to give more flexible memory options for running virtual machines. Dynamic Memory is frequently compared to vSphere memory optimization techniques. Unfortunately there are quite some misconceptions wandering around here, so I thought it would be interesting to do some investigation on the subject and publish the results on viktorious.nl. Time to clear up some things! Read on to learn more about Dynamic Memory and how it compares to vSphere 5.1 memory optimization techniques...

Hyper-V 2012 Dynamic Memory

Dynamic memory, as stated before, is build in Hyper-V version 3 which is part of Windows Server 2012. Dynamic Memory is improved compared to the first version of this technology available in Hyper-V version 2. It's a bit oversimplified, but one could compare dynamic memory (as a concept) with vSphere's memory ballooning feature. This comparison is not 100% valid...but it gives you an impression of what it does. Dynamic memory is used to reallocate memory between virtual machines that are running on a Hyper-V host. The idea behind this concept is to give virtual machines only the memory they need. So, if a virtual machine has a peak usage of 4 GB but only for 5% of the time, Hyper-V is capable of reallocating the memory of this particular virtual machine for the remaining 95% to other virtual machines. Important here, Hyper-V will never over-commit...thus provide more memory to the virtual machines than is physical available. Dynamic memory is just about memory reallocation. The advantage here is that if memory peak usage of the virtual machines is spread out through a period of time, Hyper-V is capable of moving the memory to the virtual machines that peak in memory usage and thus remove it from other less memory demanding virtual machines. Note: Dynamic memory is only available for Windows based virtual machines. More specifically: Windows 2003 SP2 and higher, Windows 7 and Windows 8. Linux cannot leverage the technology.

Dynamic Memory Configurable Options

To set some boundaries you have to following configurable options considering Dynamic Memory:

Startup RAM - This is the amount of memory the virtual machine will be started with;
Minimum RAM - This is the low value of the guest OS will be allowed to use. Hyper-V will never take more memory away than allowed by this value. This is a new setting for Windows 2012 Dynamic Memory. Minimum RAM is typically the same or lower than Startup RAM.
Maximum RAM - This is the amount of RAM that Hyper-V will give to the guest, this will determine the maximum share for a virtual machine. Maximum RAM is specifically higher than Startup RAM (and of course minimum RAM).
Memory buffer - The memory buffer specifies how much (extra) memory a virtual machine will actually get compared to the memory actually required by the virtual machine (OS + applications).
Memory weight - Memory weight will determine a relative prioritization if memory is scarce and the Hyper-V cannot satisfy memory request. Compare this to 'memory shares' in vSphere.

You will need knowledge of operating system and application memory requirements running in the guest to set the correct values for all the virtual machines that are using Dynamic Memory. Dynamic Memory will only work after configuring these values. A virtual machine will startup with "Startup RAM" GB of memory; this amount of memory can be increased to a maximum of "Maximum RAM" GB of memory. Decreasing the available memory is achieved through the synthetic memory driver which should be available in the Guest OS. You can compare this driver with the balloon driver available on ESXi.

Hypervisor Swapping: Smartpaging

On top of this (new in W2K12) Hyper-V can also leverage a memory swapping technique called "Smart Paging". This technology will leverage disk resources as additional, temporary memory, but only when more memory is required to restart a virtual machine:

This approach has both advantages and drawbacks. It provides a reliable way to keep the virtual machines running when no physical memory is available. However, it can degrade virtual machine performance because disk access speeds are much slower than memory access speeds. To minimize the performance impact of Smart Paging, Hyper-V uses it only when all of the following occur:

The virtual machine is being restarted.

No physical memory is available.

No memory can be reclaimed from other virtual machines that are running on the host.

Smartpaging will close the gap between the Minimum RAM and Startup RAM in the case the configured startup RAM is not available in the physical RAM when rebooting a virtual machine. In this case a Hyper-V will use the disk as a temporary source for virtual machine RAM. This results in a performance degrade, but only during startup...thus assuming the booting virtual machine needs more memory during startup than during normal operations. As a VMware administrator you might think at this point, why do I have to configure all these dynamic memory settings? Well because Hyper-V will never over-commit (taking into account the smartpaging in case of a vm reboot), the available memory to all virtual machines will never be more than the physical available memory minus memory overhead (e.g. the Windows parent OS that's running on your host). So, Hyper-V has to do a calculation before you can power up a virtual machine. Note: You can set (or pre-configure) most of these (almost similar) settings in a VMware environment as well (think of memory shares, memory reservation). In most cases this is not a best practice in a vSphere environment because it reduces flexibility. Read on to learn more about this. If you choose to NOT use Dynamic Memory, because you didn't configure it or when running Linux as a Guest OS, the memory will be 'reserved' for the fully 100% (remember, the memory has to be available in the physical RAM). When using Dynamic Memory, you're actually creating a dynamic memory reservation. You set the minimum & maximum reservation for memory usage and then Hyper-V will automatically move or reallocate memory between the boundaries depending on the memory pressure on a host.

vSphere 5.1 Memory Techniques

Now let's talk about memory techniques available in vSphere 5.1. vSphere 5.1 leverages four technologies that are available for all guest OSes (there's no restriction here) running on ESXi. You might think four techniques? I thought there were only three? Well, actually this changed quite a while ago. The four technologies are:

Transparent Page (Memory) Sharing

Transparent Page Sharing (TPS) is a memory de-deplucation technique. TPS leverages CPU idle time (so you can neglect performance impact) and scans ESXi memory pages. When identical memory pages are found, these pages will be shared. Actually this means that one physical memory page can (and will be used) several times by the same and/or different virtual machines.I've seen some posts about people worrying about security and performance in this case: "However, in practice, you have just opened a HUGE security hole [by enabling TSP] because now two different machines are sharing the same memory space. This is not allowed in high security environments and is risky in all environments. Additionally this is very expensive. In order to use this technology, the hypervisor must hash all the memory pages and then compare the hashes. If the hashes are identical, it then has to compare the actual pages to make sure they are the same. Then when a guest actually rights to that shared space the hypervisor, will page fault and the error handler for the page fault will create a local copy of the page, then allow the right to happen on its own dedicated memory page. This is incredibly expensive in terms of CPU utilization and yes, you guessed it, expensive in memory utilization while doing all these comparisons." Well, let's first conclude that shared memory is always read-only of course not read/write...from a conceptual perspective this is impossible. Is there still a security risk? Well, the question here is more fundamental: because the physical memory is shared by definition in a virtual environment (this counts for both Hyper-V and ESXi) the question you should ask yourself is "Do I trust the memory manager of my virtualization platform?" TSP is not introducing an additional risk here, the memory manager of ESXi just includes advanced functionality which can de-duplicate memory. On top of that vSphere 5.0 has achieved Common Criteria Certification at EAL4+ (5.1 is in evaluation) and VMware is deploying this technique for several years. More info on EAL here. Because searching duplicate memory pages leverages CPU idle time, the performance penalty for this process can be neglected. When a write is executed to a shared memory page, ESXi will run a Copy on Write (COW) action to create a unique memory page again. The steps are: write memory and change the memory pointer... incredible expensive? Not really, because we had to write the memory page anyway. Just a smart mechanism offering additional memory capacity at no (very little) cost. TSP will decrease actual memory pressure on the ESXi host. Some people are worrying that TSP is not so effective anymore because a modern OS leverages so called "large pages". There's some information on this in this KB article: "In hardware-assisted memory virtualization systems, ESX will preferentially back guest physical pages with large host physical pages (2MB contiguous memory region instead of 4KB for regular pages) for better performance. If there is not a sufficient 2MB contiguous memory region in the host (for example, due to memory overcommitment or fragmentation), ESX will still back guest memory using small pages (4KB). ESX will not share large physical pages because:

The probability of finding two large pages that are identical is very low.
The overhead of performing a bit-by-bit comparison for a 2MB page is much higher than for a 4KB page."

One final word on TSP: Although TSP is a technique to overcommit, this doesn't mean the actual physical memory load is 100%. When your policy is to have a maximum physical memory load of 80%, TSP allows you to distribute (as an example) 20% more memory within this 80% memory load resulting in a 96% memory load when TSP wouldn't do a thing....get the point?

Memory Ballooning

Memory ballooning is the ESXi memory reclamation technique and can be compared to the Dynamic Memory option in Windows Server 2012. Memory ballooning will only work when there's high memory pressure on the host and can loan memory from one virtual machine to another virtual machine. Ballooning uses VMware Tools and uses the Guest OS swapping (just like Dynamic Memory) to free up Guest OS memory and loan this to another virtual machine that needs more memory. Ballooning works for both Windows and Linux guests as long as the VMware Tools are installed. The guest OS is in a much better position than the ESXi hypervisor to decide which memory regions it can give up without impacting performance of key processes running in the VM. At this point you might think, in Windows Server 2012 I have several options to tune Dynamic Memory behavior...what options has ESXi available? Well you can use memory reservation and memory shares to change ballooning and swapping behavior. Memory reservation guarantees the availability of memory for a virtual machine, with memory shares you can set a relative priority on virtual machines when memory is scarce. Note: by default, ESXi will never balloon more than 65% of the configured memory. In a normal situation I would advice not to configure reservation and shares. The ESXi hypervisor (VMkernel) is a intelligent hypervisor which performs very good with default reservation and shares settings. Only in case you want to change memory priorities or guarantee resources for a particular virtual machine you should change these settings. This makes the management of the environment a lot more easier and reduces administrative overhead.

VMkernel (Hypervisor) Swapping leveraging the vswp file

When memory pressure on a host is too high and both TSP and Ballooning cannot satisfy memory requirements, ESXi can use Hypervisor Swapping. In this case memory pages are swapped to disk. This swapping has of course a performance impact, although with the introduction of SSD disk (and swapping to these type of disks) ideas about this type of swapping are changing, because the performance degrade might be acceptable. VMware introduced the concept "swap to host cache" in vSphere 5, a good article about this technology is available on yellow-bricks.com. When an ESXi is showing VMkernel swapping this can be ok for a short period of time....when it last longer you might want to increase available memory. Especially with swapping always look to "swap out" en "swap in" activity because this will degrade performance. Memory pages just 'sleeping' in VMkernel swap have less performance impact.

Memory Compression (yes, that's number 4)

vSphere 4.1 introduced the concept of memory compression, an additional technology to reduce hypervisor swapping. The idea is to delay the need to swap hypervisor pages by compressing VM memory pages that are candidates for swap to disk. This compressing and decompressing is faster that performing Disk I/O operations. Memory Compression will only take place when there's contention for physical memory resources.

To summarize...

Both Windows Server 2012 Hyper V and ESXi 5.1 leverage some intelligent memory optimization techniques. Where Hyper-V version 3 has Dynamic Memory and Smart Paging, ESXi 5.1 can leverage Transparent Page Sharing, Guest Ballooning, Hypervisor Swapping and Memory Compression. Hyper-V Dynamic Memory is designed to offer flexibility by moving the available memory around the virtual machines, with Smart Paging ready to do some paging to disk in case of a VM reboot in a situation of high memory pressure. VMware has memory de-deduplication on board. This feature enables you to run more virtual machines in the same amount of memory and thus achieve a higher consolidation ratio (thus you will need less physical servers or less memory available in your servers). Although recently there has be some discussion about effectiveness and the actual increase in capacity, my personal experience is that TSP will succeed in sharing at least 20% of the memory between virtual machines. On top of that VMware also uses ballooning, swapping and compression techniques to guarantee maximum flexibility. From an administrative standpoint there's a different approach regarding memory optimization. Hyper-V demands you to pre-configure dynamic memory settings, where as ESXi memory techniques work just right out-of-the-box....allowing you to set certain values depending on the exact use-case. I hope this article helped you to better understand memory optimization techniques. I am looking forward to your comments! For further reading I suggest you to take a look at these articles:

Virtual Memory Management: Dynamic Memory-Much Different Than Memory Over Commit - Dan Stolts (got some inspiration from this article)
Hypervisor Memory Management Done Right - Eric Horschman (got some inspiration from this article as well)
Swap to host cache aka swap to SSD? - Duncan Epping
Hyper-V Dynamic Memory Overview - Microsoft
Windows 7 Transparent Page Sharing and the ASLR story - Andre Leibovici
vSphere 5 memory management explained (worth a read!): part 1 and part 2 - Erik Scholten of vmguru.nl
And some good discussion here: My Frustration with HyperV, do you really save anything? - Justin Paul

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Meet the vExperts at VMware Forum NL

viktorious — Mon, 29 Apr 2013 20:55:29 +0000

On June 4th 2013 the annual VMware Forum will take place in Den Bosch in The Netherlands. VMware Forum is a one day full conference to update you on the latest VMware technology. The event is traveling around the world and will visit cities in Europe, Middle East and Africa. Visit the VMware Forum website for more information on this event.

The Dutch Genius Bar @ VMware Forum

For the first time VMware Forum The Netherlands will host a real Genius Bar! The Genius Bar is staffed some of the Dutch VMware bloggers, who will be ready to answer all your questions. The Genius Bar is initiated by Eric Sloof of ntpro.nl who will be accompanied by Bouke Groenescheij, Duco Jaspers, Gabrie van Zanten, Joep Piscaer and yours truly. I would be very happy to answer any question on vSphere, vCloud Director, vCenter Operations and Site Recovery Manager! So don't wait, and register for VMware Netherlands now. The event is free but you have to register to attend. Hope to CU at June 4th in Den Bosch. Read Eric's post at the Dutch VMware blog for more information.

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Upgrading to vSphere 5.1 Update 1? First check interoperability!

viktorious — Sat, 27 Apr 2013 06:39:03 +0000

Update April 28th 2013: Additional information on View 5.1 / vSphere 5.1 Update 1 compatibility! This week VMware released update 1 for vSphere 5.1. vSphere 5.1 update 1 contains several bugfixes, support for new OSes and improved hardware support. Although upgrading might be a good idea, always ask yourself what the dependencies are between vSphere and other solutions in your datacenter. Investigate the interoperability between vSphere 5.1 Update 1 and other VMware solutions plus (3rd party) backup solutions and monitoring solutions. For the interoperability with other VMware products, you can check the Interoperability Matrix, which is available on-line. When upgrading to VMware vCenter 5.1 Update 1 and ESXi 5.1 Update 1, verify you're running the latest version for the following add-on products:

Site Recovery Manager 5.1 Update 1 required: SRM 5.1U1 is compatible with both vCenter 5.1 and vCenter 5.1 Update 1. SRM 5.1 U1 is not compatible with vCenter 5.0.
vCenter Operations Manager 5.7 required. This version is compatible with all 4.x and 5.x vCenter servers.
vCenter Update Manager 5.1 Update 1, this version is only compatible with vCenter 5.1 Update 1.
vCloud Director 5.1.2 is required and compatible with vSphere 5.x (including 5.1 update 1).
vCloud Networking & Security 5.1.2 is required and compatible with vSphere 5.x (including 5.1 update 1).
vCenter 5.1 Update 1 can manager ESXi all versions of ESXi 4.x and 5.x.
Notice: There is some contradictory information about VMware Horizon View compatibility. The VMware Interoperability Matrix tells 5.2 is not compatible with vCenter 5.1 Update 1, while this KB article tells View 5.2 is compatible. I've asked VMware to clear up some things here. Kudos to Jay Weinshenker for commenting on this issue. I except View 5.2 to be compatible.VMware View 5.2 is compatible with vCenter 5.1 Update 1, the compatibility matrix was updated by VMware!

Happy upgrading! The full release notes for vCenter are available here, ESXi release notes here. I also suggest to read VMware KB article 2037630 which is about the update sequence for vSphere 5.1 Update 1 and its compatible products.

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vCloud Director: About user/role management and empty LDAP groups

viktorious — Wed, 24 Apr 2013 07:35:13 +0000

When it comes to user & role management vCloud Director gives you various options. First of all, you can configure users on the cloud provider level or per organization. When talking about user management at cloud level you have just one role available: the system administrator. Thus every cloud provider user is an system administrator and will have access to all vCloud Director settings. This user account will also act as an Organization Administrator for every organization (and has also access to all the vApps). At vCloud Director organization level you have different roles available. These roles are customizable and you can create new roles if necessary. These roles are defined at cloud provider level and are available for all the configured organizations. When configuring users at cloud provider level, you have the following options:

Create vCloud Director integrated users. These users (including passwords) will be saved to the vCD database.
Use LDAP users by connecting to a LDAP directory, e.g. Microsoft Active Directory. You can configure LDAP through Administration->LDAP.
Use SSO useraccounts, you can choose to import to SSO accounts and assign them the system administrator role. This works out of the box.

It is a best practice to create at least one vCloud Director integrated user, this ensures access to the environment when the LDAP connection is down. For organizations you have four options when it comes to useraccounts:

Create vCloud Director integrated users.
Use the VCD system LDAP service. Important: in this case the Cloud Provider LDAP service is used. Configure this option through the organization->Administration->LDAP->VCD system LDAP service.
Use a custom LDAP service per vCloud Director organization. Configure this option through organization->Administration->LDAP->Custom LDAP Service.
Use a SAML identity provider for the useraccounts, using Administration->Federation.

In this case it is again very useful to create at least one non-LDAP/SAML useraccount which guarantees access to the vCD environment.

About vCloud Director empty LDAP groups

When using LDAP it is a very good idea to leverage LDAP groups for role assignment. In this case you will link a role to a LDAP group. Depending on the LDAP group membership of a user (managed through your directory), vCloud Director roles are assigned. After right clicking and LDAP group and choosing properties, you can link a role to the LDAP group and see which users are members of the group. Important here: by default the group will not show all LDAP group members. Only after a group member (user) logs on to vCloud Director, the username will be displayed in the group. In the example on the right, user "vbe" is the only user that already has logged on to the cloud environment.

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