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Tag Archives: Instant Clones

VMware Horizon 7 – Associate Instant Clone Virtual Machines

Matt_freyby Matt Frey

Being a field consultant affords me the opportunity to get in the nitty gritty with many of our customers. One of my favorite aspects of this role is helping customers address their business’s needs in a hands-on fashion. During one of my recent engagements, a customer asked, “How do I identify which parent VMs belong to which Instant Clone Desktops?” Since I’m sure that question will be asked by many others, I thought I would take some time to show how that process is carried out.
Horizon 7 - Associate IC VMs

 I hope that this article helps in shining light on the relationship between the various Instant Clone components. If your team needs additional resources I recommend you check out our Horizon Certification courses as well as the many Hands On Labs.

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Matt Frey is a Consultant in the End User Computing branch of Professional Services with over 15 years’ experience in the IT industry. He currently holds a VCP6-DTM and VCAP6-DTM and specializes in bringing enhanced value to customers by leveraging VMware’s strong EUC portfolio.

VMware Horizon 7 Instant Clones Best Practices

Dale CarterBy Dale Carter

Recently, I have been working with Instant Clones in my lab. Although I have found this easy to get up and running (for more information, see my blog here), it hasn’t been easy to find best practices around configuring Instant Clones, as they are so new.

I reached out to the engineering team, and they provided me with the following best practices for using Instant Clones in VMware Horizon 7.0.2.

Check OS Support for Instant Clones

The following table shows what desktop operating systems are supported when using Instant Clones.

Guest Operating System Version Edition Service Pack
Windows 10 64-Bit and 32-Bit Enterprise None
Windows 7 64-Bit and 32-Bit Enterprise and Professional SP1

For more information, see the architecture planning guide.

Remote Monitor Limitations

If you use Instant Clone desktop pools, the maximum number of monitors that you can use to display a remote desktop is two, with a resolution of up to 2560 X 1600. If your users require more monitors or a higher resolution, I recommend using a Linked Clone desktop pools for these users.

For more information, see the architecture planning guide.

Instant Clones on vSAN

When running Instant Clones on vSAN it is recommended to the R5 configuration that will have the following settings

Name Checksum Rain Level Duplication and Compression Client Cache Sparse Swap
R5 Yes 5 No Enabled Disabled

For more information, see the VMware Horizon 7 on VMware Virtual SAN 6.2 All-Flash, Reference Architecture.

Unsupported Features when using Instant Clones

The following features are currently not supported when using Instant Clones.

View Persona Management

The View Persona Management feature is not supported with Instant Clones. I recommend the User Environment Manager for managing the user’s environment settings.

For more information, see the architecture planning guide.

3D Graphics Features

The software and hardware accelerated graphics features available with the Blast Extreme or PCoIP display protocol are currently not supported with Instant Clones desktops. If your users require this feature, I recommend you use a Linked Clone desktop for them.

For more information, see the architecture planning guide.

Virtual Volumes

VMware vSphere Virtual Volumes Datastores are currently not supported for Instant clone desktop pools. For Instant Clone desktop pools, you can use other storage options, such as VMware Virtual SAN.

For more information, see the architecture planning guide.

Persistent User Disk

Instant Clone pools do not support the creation of a persistent virtual disk. If you have a requirement to store a user’s profile and application data on a separate disk, you can use the writeable disk feature of VMware App Volumes to store this data. The App Volumes writeable volume can also be used to store user installed applications.

For more information, see the architecture planning guide.

Disposable Virtual Disk

Instant Clone pools do not support configuration of a separate, disposable virtual disk for storing the guest operating system’s paging and temp files. Each time a user logs out of an instant clone desktop, Horizon View automatically deletes the clone and provisions and powers on another instant clone based on the latest OS image available for the pool. Any guest operating systems paging and temp files are automatically deleted during the logo operation.

For more information, see the architecture planning guide.

Hopefully, this information will help you configure Instant Clones in your environment. I would like to thank the VMware Engineering team for helping me put this information together.


Dale Carter is a Senior Solutions Architect and member of the CTO Ambassadors. Dale focuses in the End User Compute space, where Dale has become a subject matter expert in a number of the VMware products. Dale has more than 20 years’ experience working in IT having started his career in Northern England before moving the Spain and finally the USA. Dale currently holds a number of certifications including VCP-DV, VCP-DT, VCAP-DTD and VCAP-DTA. For more blog post from Dale visit his website athttp://vdelboysview.com

The Anatomy of an Instant Clone

By Travis Wood

If you’ve used Horizon View over the last few years, then you most likely have come across linked clones. Linked clones use a parent image, called a “replica,” that serves read requests to multiple virtual machines (VMs), and the writes in each desktop are captured on their own delta disk. Replicas can also be used to change desktop update methodologies; instead of updating every desktop, you can update the parent image and recompose the rest of the desktops.

Horizon 7 has introduced a new method of provisioning with Instant Clones. Instant Clones are similar to linked clones in that all desktops read from a replica disk and write to their own disk, but Instant Clone takes it one step further by doing the same thing with memory. Instant Clones utilize a new feature of vSphere 6 where desktop VMs are forked (that is, Instant Clones are created) off a running VM—instead of cloning a powered-off VM—which provides savings for provisioning, updates, and memory utilization.

Golden Image

With Instant Clones you start with your golden image, in a way that is similar to linked clones. The golden image is the VM you install the operating system on, then join to the domain, and install user applications on; you follow the same OS optimizations procedures you would use for Instant Clones.

When you’re done, release its IP address, shut it down, and create a snapshot. Now you are ready to create your Instant Clone desktop pool. This VM should have VM Tools installed, along with the Horizon Agent with the Instant Clone module. It is NOT possible to have the Instant Clone and Composer modules co-installed, so you will always need different snapshots if using Instant Clones and linked clones from the same golden image. Reservations can be set on the golden image and they will be copied to the Instant Clones, reducing the size of the VSwap file. It is important to note that the golden image must be on storage that’s accessible to the host you are creating your Instant Clone desktop pool on.

Template

When you create your pool, Horizon will create a template. A template is a linked clone from your golden image, created on the same datastore as the golden image. It will have the name cp-template, and will be in the folder ClonePrepInternalTemplateFolder. Template disk usage is quite small, about 60 MB. There will be an initial power-on after the template is created, but it will then shut off.

TWood_Horizon Template

Replica

Next, Horizon will create a replica, which is the same as a Linked Clone replica. It is a thin-provisioned, full clone of the template VM. This will serve as the common read disk for all of your Instant Clones, so it can be tiered onto appropriate storage through the Horizon Administrator console, the same way it is done with Linked Clones. Of course, if you are using VSAN, there is only one datastore, so tiering is done automatically. Horizon will also create a CBRC Digest file for the replica. The replica will be call cp-replica-GUID and will be in the folder ClonePrepReplicaVmFolder. The disk usage of the replica will be depend on how big your Gold Master is, but remember, it’s thin provisioned and not powered on, so you will not have VSwap functionality.

TWood_Horizon Replica

Parent

Horizon will now create the final copy of the original VM, called a parent, which will be used to fork the running VMs. The parent is created on every host in the cluster; remember, we are forking running VMs here, so every host needs to have a running VM. These will be placed on the same datastore as the desktop VMs, where there will be one per host per datastore. Because these are powered on, they have a VSwap file the size of the allocated vMEM. In addition, there will be a small delta disk to capture the writes booting the parent VM and the VMX Overhead VSwap file, but this—and the sum of the other disks—is relatively small, at about 500 MB. These will be placed in ClonePrepReplicaVmFolder.

TWood_Horizon Parent

Something you’ll notice with the parent VM is that it will use 100% of its allocated memory, causing a vCenter alarm.

TWood_vCenter Alarm

TWood_Virtual Machine Error

Instant Clones

OK! At this point, we are finally ready to fork! Horizon will create the Instant Clones based on the provisioning settings, which can be upfront or on-demand. Instant Clones will have a VSwap file equal to the size of the vMEM—minus any reservations set on the Gold Master, plus a differencing disk.

The amount of growth for the differencing disk will depend on how much is written to the local VM during the user’s session, but it is deleted on logout. When running View Planner tests, this can grow to about 500 MB, which is the same as when using View Planner for Linked Clones. The provisioning of Instant Clones will be fast! You’ll see much lower resource utilization of your vCenter Server and less IO on your disk subsystem because there is no boot storm from the VMs powering on.

TWood_vCenter Server

Conclusion

Instant Clones are a great new feature in Horizon 7 that take the concept of Linked Clones one step further. They bring the advantages of:

  • Reducing boot storms
  • Decreasing provisioning times
  • Decreasing change windows
  • Bringing savings to storage utilization

Instant Clones introduce a number of new objects: replicas, parents, and templates. It is important to understand not only how these are structured, but also their interrelationships, in order to plan your environment accordingly.


Travis is a Principal Architect in the Global Technology & Professional Services team, specializing in End User Computing.  He is also a member of the CTO Ambassadors program which connects the global field with R&D and engineering.