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VCAP7-DTM Design Exam, Part 10

In part 10 of my VCAP7-DTM Design exam series we take a look at the Horizon 7 Enterprise Reference Architecture.

To be honest, I didn’t study that much the last two weeks but I checked a few documents about App Volumes, Mirage, ThinApp and User Environment Manager.

This time I would like to summarize what I have learned from the reference architecture and the VMworld 2018 session called Architecting Horizon 7 Enterprise: The Official Reference Architecture (WIN3451BUR).

I only focus on the component design part since I already covered topics like use cases, business drivers, design methodology etc.

Horizon 7

A successful deployment depends on good planning and a very good understanding of the platform. The core elements include Connection Server, Composer, Horizon Agent and Horizon Client. Part 4 to part 9 cover the Horizon 7 component design and also provide more information on the following components.

Horizon 7 Logical Architecture

Identity Manager

VMware Identity Manager (VIDM) can be implemented on-premises or in the cloud, a SaaS-based implementation. If you decide to go with the SaaS implementation, a VIDM connector needs to be installed on-prem to synchronize accounts from Active Directory to the VIDM service in the cloud.

If cloud is no option for you, you still have the possibility for the on-prem deployment and use the Linux-based virtual appliance. There is also a Windows-based installer available which is included in the VMware Enterprise Systems Connector. VMware’s reference architecture is based on the Linux appliance.

VMware Identity Manager Architecture

Syncing resources such as Active Directory and Horizon 7 and can be done either by using a separate VMware Identity Manager Connector or by using the built-in connector of an on-premises VMware Identity Manager VM. The separate connector can run inside the LAN in outbound-only connection mode, meaning the connector receives no incoming connections from the DMZ.

VIDM comes with an embedded PostgreSQL database, but it’s recommended to use an external database server for production deployments.

For high availability, based on your requirements, at least two VIDM appliances should be deployed behind a load balancer. After you have deployed your first appliance, you simply clone it and assign a new hostname and a new IP address.

App Volumes

As you still may know from part 8, App Volumes has two functions. The first is the delivery of applications for VDI and RDSH. The second is the provision of writable volumes to capture user-installed applications and the user profile.

app volumes architecture

For high availability, always use at least two App Volumes Managers which are load-balanced.

AppStacks are very read intensive, hence, you should place AppStacks on storage that is optimized for read operations. Writable volumes should be placed on storage for random IOPS (50/50). There reference architecture uses vSAN to provide a single highly available datastore.

For the SQL database it is recommended using an AlwaysOn Availability Group.

User Environment Manager

When User Environment Manager design decisions need to be made, you have to think about user profiles (mandatory, roaming, local) and folder redirection. As already described in part 9, VMware recommendation is to use mandatory profiles and folder redirection. Use appendix B if you need help configuring the mandatory profile.

vmware user environment manager

The first key design consideration is using DFS-R to provide high availability for the configuration and user shares. Note: Connect the management console only to the hub member when making changes. DFS-R will replicated those changes to the spoke members.

The second consideration one is using GPO loopback processing.

Unified Access Gateway

In part 6 I mentioned that a UAG is typically deployed within the DMZ.

VMware Unified Access Gateway

UAG appliances are deployed in front of the Horizon 7 Connection Servers and sit behind a load balancer. The Unified Access Gateway also runs the Content Gateway as part the AirWatch (WorkspaceONE UEM) service.

You have two sizing options during the appliance deployment:

  • Standard (2 vCPU, 4GB RAM, 2’000 Horizon server connections, 10’000 AirWatch service connections)
  • Large (4 vCPU, 16GB RAM, 2’000 Horizon server connections, 50’000 AirWatch service connections)

As you can see, the big difference here are the estimated AirWatch service connections per appliance. In production you would deploy dedicated UAG appliances for each service. Example:

  • 2 standard size UAGs appliances for 2’000 Horizon 7 sessions (n+1)
  • 3 large size UAG appliances for 50’000 devices using Content Gateway and per-App Tunnel which gives us a total of 100’000 sessions. The third appliance is for high availability (n+1)

vSphere and Physical Environment

The software-defined data center (SDDC) is the foundation that runs all infrastructure servers and components. The products and the licensing for the foundation are outside of the Horizon 7 product (except vSAN), but are required to deliver a complete solution.

And in my opinion this is what makes the whole solution so brilliant. Even I work for VMware, I would never say from the beginning that Horizon is better than XA/XD. This was also the case when I worked as a consultant for Citrix before I joined VMware in May 2018.
It depends on the requirements and use cases which need to be satisfied. That are the most important things if you choose a vendor or a specific technology. Our goal is to make the customer happy! 🙂

But I would say that VMware Horizon including WorkspaceONE is very hard to beat if you use the complete stack! But that’s another topic.

The vSphere infrastructure in the reference architecture includes vSAN and NSX. In part 5 I covered the basics of vSAN, but I think I maybe need to write a short overview about NSX and how you can use it with Horizon.

vSAN provides a hyper-converged storage optimized for virtual machines without the need for an external SAN or NAS. This means that the physical server not only provides the compute and memory resources, but also storage in a modular fashion. You can use vSAN for the management and resource block  and follow a hybrid approach for the management resources and use all-flash vSAN for the Horizon resources.

VMware vSAN

I will not cover the vSphere design, but it’s important to understand that all components are operating redundantly and that you have enough physical resources to meet the requirements.

vSphere Networking

A general recommendation is to use at least 10 GbE connections, to separate each traffic (mgmt, VM traffic, vSAN, vMotion) and make sure that each of them has sufficient bandwidth.

NSX for vSphere

NSX provides several network-based services and performs several security functions within a Horizon 7 implementation:

  • Protects VDI infrastructure
  • Protects desktop pool VM communication with applications
  • Provides user-based access control (user-level identity-based micro-segmentation)

VMware NSX for vSphere

If you want to use NSX you have to think about a NSX infrastructure design as the NSX platform adds new components (e.g. NSX manager) and new possibilities (distributed firewall and identity firewall).

The most important design consideration for Horizon 7 is the concept of micro-segmentation. In the case of Horizon 7, NSX can block desktop-to-desktop communications, which are normally not needed or recommended. Each VM can now be its own perimeter and this desktop isolation prevents threats from spreading:

NSX isolation

The Horizon 7 reference architecture of probably the best document to prepare yourself for the VCAP7-DTM exam. What do the current VCAP7-DTM certified  people say? What else needs to be covered? Jump to part 11

VCAP7-DTM Design Exam, Part 5

This is the fifth part of my VCAP7-DTM Design exam series. In part 4 I covered the creation of a physical design for vSphere and Horizon components. This time we take a look at section 4 of the blueprint, the creation of a physical design for horizon storage:

Section 4 – Create a Physical Design for Horizon Storage
Objective 4.1 – Create and Optimize a Physical Design for Horizon Infrastructure Storage
Objective 4.2 – Create and Optimize a Physical Design for View Pool Storage
Objective 4.3 – Create and Optimize a Physical Storage Design for Applications
Objective 4.4 – Create and Optimize a Tiered Physical Horizon Storage Design
Objective 4.5 – Integrate Virtual SAN into a Horizon Design

This article is not a comparison between HCI and traditional storage architecture and if you build hosts by yourself or buy Dell EMC’s VxRail or any other vSAN ReadyNode.

Since it is VMware’s strategy to push vSAN and get away from traditional storage, I only cover vSAN. For my VCDX design I will also move away from traditional storage and use vSAN – it’s also my customer’s strategy. The price for flash storage is decreasing constantly and makes a hybrid vSAN architecture less attractive – at least for our use cases.

In general the storage design of a Horizon implementation is very critical. You have to think about capacity, growth capacity, data/object placement, disaster recovery, kind of SSD disks and so on. But in my opinion, HCI or vSAN makes your life a lot easier and simplifies the storage deployment.

If you fail to correctly size the storage and I/O capacity, your customer’s user experience will suffer or the deployment of new desktops is not possible anymore. So, storage performance and sizing is vital for the satisfactory of your customers and their users!

All-Flash or Hybrid Architecture

The first thing you have to figure out and define is the vSAN platform you are going to deploy – All-Flash or hybrid architecture. A All-Flash vSAN configuration aims at delivering very high IOPS with low latencies. Also in a All-Flash configuration you use two different grades of (flash) disks:
lower capacity and higher endurance device for the capacity tier and
more cost-effective and higher capacity disks for the capacity tier

There is no read cache available in a All-Flash configuration as all data is directly read from the capacity tier. Because you aim for extremely high IOPS, make sure you provide a dedicated 10Gb network for the vSAN traffic.

You can enable the deduplication and compression setting (not available when using a hybrid vSAN) in the vSAN cluster to reduce redundant copies of blocks within the same disk group to one copy and to compress the blocks after they have been deduplicated.

Erasure Coding (RAID 5/6 is only available with All-Flash) provides the same level of redundancy as mirroring, but with a reduced capacity requirement. In general, erasure coding means breaking data into multiple pieces and spread them across multiple devices, while adding parity data in the event data gets corrupted or lost. This is a good and short video about this feature:

If you want to use Horizon together with a vSAN Stretched Cluster, there are some limitations. Please read my article VMware Horizon 7.x and vSAN Stretched Cluster.

When using vSAN without further adjustments, your virtual desktops and infrastructure servers are using the default vSAN storage policy. For infrastructure servers this might be okay, but for our desktops we need to create a new policies. Cormac Hogan has very good material about Horizon and vSAN Storage Policies:

HORIZON VIEW 7 ON VSAN – POLICIES REVISITED
HEADS UP! HORIZON VIEW 6.1 AND AF-VSAN POLICIES

The Number of Failures to Tolerate defines the number of host, disk or network failures a storage object can tolerate. This number of Failures to Tolerate (FTT) has the greatest impact on your capacity in a vSAN cluster. Based on your configured availability requirements for a VM, the settings in the policy can lead to a higher consumption on the vSAN datastore (more copies of your data). For “n” failures tolerated, n+1 copies of the object are created and 2n+1 hosts are required.
Consider to configure FTT = 0 for the OS disk for linked-clone floating pools or if you use full-clone non-persistent desktops. If vSAN should experience a failure, only non-persistent data will be lost.

I hope this information was helpful even we didn’t go to deep. If you need to know more about vSAN, then you’ll find tons of documents and other blogs about this technology.

In part 6 I’ll try to give you more information about the design for a Horizon network.

VMware Horizon 7.x and vSAN Stretched Cluster

In Switzerland sites are often located in the same data center building and two separate rooms represent these sites. To keep management and the architecture simple, some customers or partners would like to take advantage of a vSAN Stretched Cluster.

This question came up several times already at the product management: “Are Instant Clone desktops supported in combination with vSAN Stretched Clusters? And can we use App Volumes?

The short answer of our product management was that Horizon 7.x (all clones) and a vSAN Stretched Cluster are supported, but that we advise customers to follow the reference architecture design and to test the scalability of the combination of Horizon 7 and a vSAN Stretched Cluster. The caveat is that App Volumes is not supported in this scenario.

A few days ago our VMware Workspace ONE and VMware Horizon 7 Enterprise Edition On-premises Reference Architecture only advised to work with two separate sites, connect them via Cloud Pod Architecture (CPA) and use replication features (e.g. for AppStacks, user profile etc.) to achieve something like an active/active architecture:

cloud pod architecture

But it was not 100% clear if it’s supported to use non-persistent desktops together with a vSAN Stretched Cluster. This gap has been closed with the appendix H:

This new appendix is saying that a stretched active/active architecture is not supported and the use case described in the RA is for full clones only. So, please carefully read our guidelines when working with vSAN Stretched Clusters and Horizon 7.

App Volumes Caveat: There is no support for App Volumes at this time when using a vSAN Stretched Cluster.