When you create an automated linked-clone farm, you can configure certain settings.

Table 1. Worksheet: Configuration Settings for Creating an Automated Linked-Clone Farm
Setting Description Fill in Your Value Here
ID Unique name that identifies the farm in Horizon Console.
Description Description of this farm.
Access group

Access group in which to place all the pools in this farm.

For more information about access groups, see the role-based delegated administration chapter in the Horizon 7 Administration document.

Default display protocol Select VMware Blast, PCoIP or RDP. RDP applies to desktop pools only. The display protocol for application pools is always VMware Blast or PCoIP. If you select RDP and you plan to use this farm to host application pools, you must set Allow users to choose protocol to Yes. The default is PCoIP.
Allow users to choose protocol Select Yes or No. This setting applies to RDS desktop pools only. If you select Yes, users can choose the display protocol when they connect to an RDS desktop from Horizon Client. The default is Yes.
Pre-launch session timeout (applications only) Determines the amount of time that an application configured for pre-launch is kept open. The default is 10 minutes.

If the end-user does not start any application in Horizon Client, the application session is disconnected if the idle session times out or if pre-launch session times out.

If you want to end the pre-launch session after timeout, you must set the Log off disconnected session option to Immediate.

Empty session timeout (applications only)

Determines the amount of time that an empty application session is kept open. An application session is empty when all the applications that run in the session are closed. While the session is open, users can open applications faster. You can save system resources if you disconnect or log off empty application sessions. Select Never, Immediate, or set the number of minutes as the timeout value. The default is After 1 minute. If you select Immediate, the session logs off or disconnects within 30 seconds.

You can further reduce the time the session logs off or disconnects by editing a registry key on the RDS Host on which Horizon Agent is installed. Navigate to HKEY_LOCAL_MACHINE\SOFTWARE\VMware, Inc.\VMware VDM\Plugins\wssm\applaunchmgr\Params and set a value for WindowCheckInterval. The default value is 20000. This means that the poll for the empty session check is every 20 seconds, which sets the maximum time between the last application session close and session log off to 40 seconds. You can change this value to 2500. This means that the poll for the empty session check is every 2.5 seconds, which sets the maximum time between the last application close and session log off to 5 seconds.

When timeout occurs Determines whether an empty application session is disconnected or logged off after the Empty session timeout limit is reached. Select Disconnect or Log off. A session that is logged off frees up resources, but opening an application takes longer. The default is Disconnect.
Log off disconnected session Determines when a disconnected session is logged off. This setting applies to both desktop and application sessions. Select Never, Immediate, or After ... minutes. Use caution when you select Immediate or After ... minutes. When a disconnected session is logged off, the session is lost. The default is Never.
Allow Session Collaboration Select Enabled to allow users of desktop pools based on this farm to invite other users to join their remote desktop sessions. Session owners and session collaborators must use the VMware Blast protocol.
Max sessions per RDS server Determines the maximum number of sessions that an RDS host can support. Select Unlimited or No More Than .... The default is Unlimited.
Enable provisioning Select this checkbox to enable provisioning after you finish this wizard. This box is checked by default.
Stop provisioning on error Select this checkbox to stop provisioning when a provisioning error occurs. This box is checked by default.
Naming pattern Specify a prefix or a name format. Horizon 7 will append or insert an automatically generated number starting with 1 to form the machine name. If you want the number at the end, simply specify a prefix. Otherwise, specify {n} anywhere in a character string and {n} will be replaced by the number. You can also specify {n:fixed=<number of digits>}, where fixed=<number of digits> indicates the number of digits to be used for the number. For example, specify vm-{n:fixed=3}-sales and the machine names will be vm-001-sales, vm-002-sales, and so on.
Note: Each machine name, including the automatically generated number, has a 15-character limit.
Max number of machines The number of machines to be provisioned.
Minimum number of ready (provisioned) machines during View Composer maintenance operations This setting lets you keep the specified number of machines available to accept connection requests while View Composer recomposes the machines in the farm.
Use VMware vSAN Specify whether to use VMware vSAN, if available. vSAN is a software-defined storage tier that virtualizes the local physical storage disks available on a cluster of ESXi hosts. For more information, see "UsingvSAN for High-Performance Storage and Policy-Based Management" in the Setting Up Virtual Desktops in Horizon 7 document.
Select separate datastores for replica and OS disks (Available only if you do not use vSAN) You can place replica and OS disks on different datastores for performance or other reasons.
Golden Image in vCenter Select a golden image virtual machine from the list. Be aware that the list includes virtual machines that do not have View Composer Agent installed. You must not select any of those machines because View Composer Agent is required. A good practice is to use a naming convention that indicates whether a virtual machine has View Composer Agent installed.
Snapshot Select the snapshot of the golden image virtual machine to use as the base image for the farm.

Do not delete the snapshot and golden image virtual machine from vCenter Server, unless no linked clones in the farm use the default image, and no more linked clones will be created from this default image. The system requires the golden image virtual machine and snapshot to provision new linked clones in the farm, according to farm policies. The golden image virtual machine and snapshot are also required for View Composer maintenance operations.

VM folder location Select the folder in vCenter Server in which the farm resides.
Cluster Select the ESXi host or cluster on which the desktop virtual machines run.

With vSAN datastores (a vSphere 5.5 Update 1 feature), you can select a cluster with up to 20 ESXi hosts. With Virtual Volumes datastores (a vSphere 6.0 feature), you can select a cluster with up to 32 ESXi hosts.

In vSphere 5.1 or later, you can select a cluster with up to 32 ESXi hosts if the replicas are stored on VMFS5 or later datastores or NFS datastores. If you store replicas on a VMFS version earlier than VMFS5, a cluster can have at most eight hosts.

In vSphere 5.0, you can select a cluster with more than eight ESXi hosts if the replicas are stored on NFS datastores. If you store replicas on VMFS datastores, a cluster can have at most eight hosts.

Resource pool Select the vCenter Server resource pool in which the farm resides.
Datastores Select one or more datastores on which to store the farm.

A table on the Select Linked Clone Datastores page of the Add Farm wizard provides high-level guidelines for estimating the farm's storage requirements. These guidelines can help you determine which datastores are large enough to store the linked-clone disks. For details, see "Storage Sizing for Instant-Clone and Linked-Clone Desktop Pools" in the Setting Up Virtual Desktops in Horizon 7 document.

You can use shared or local datastores for an individual ESXi host or for ESXi clusters. If you use local datastores in an ESXi cluster, you must consider the vSphere infrastructure constraints that are imposed on your desktop deployment. For details, see "Storing Linked Clones on Local Datastores" in the Setting Up Virtual Desktops in Horizon 7 document..

Note: If you use vSAN, select only one datastore.
Storage Overcommit Determine the storage-overcommit level at which linked-clones are created on each datastore.

As the level increases, more linked clones fit on the datastore and less space is reserved to let individual clones grow. A high storage-overcommit level lets you create linked clones that have a total logical size larger than the physical storage limit of the datastore. For details, see "Storage Overcommit for View Composer Linked-Clone Virtual Machines" in the Setting Up Virtual Desktops in Horizon 7 document.

Note: This setting has no effect if you use vSAN.
Use native NFS snapshots (VAAI) (Available only if you do not use vSAN) If your deployment includes NAS devices that support the vStorage APIs for Array Integration (VAAI), you can use native snapshot technology to clone virtual machines.

You can use this feature only if you select datastores that reside on NAS devices that support native cloning operations through VAAI.

You cannot use this feature if you store replicas and OS disks on separate datastores. You cannot use this feature on virtual machines with space-efficient disks.

This feature is supported on vSphere 5.0 and later.

For details, see "Using VAAI Storage for View Composer Linked Clones" in the Setting Up Virtual Desktops in Horizon 7 document..

Reclaim VM disk space (Available only if you do not use vSAN or Virtual Volumes) Determine whether to allow ESXi hosts to reclaim unused disk space on linked clones that are created in space-efficient disk format. The space reclamation feature reduces the total storage space required for linked-clone desktops.

This feature is supported on vSphere 5.1 and later. The linked-clone virtual machines must be virtual hardware version 9 or later.

For details, see "Reclaim Disk Space on Linked-Clone Virtual Machines" in the Setting Up Virtual Desktops in Horizon 7 document.

Initiate reclamation when unused space on VM exceeds: (Available only if you do not use vSAN or Virtual Volumes) Type the minimum amount of unused disk space, in gigabytes, that must accumulate on a linked-clone OS disk to trigger space reclamation. When the unused disk space exceeds this threshold, Horizon 7 initiates the operation that directs the ESXi host to reclaim space on the OS disk.

This value is measured per virtual machine. The unused disk space must exceed the specified threshold on an individual virtual machine before Horizon 7 starts the space reclamation process on that machine.

For example: 2 GB.

The default value is 1 GB.

Blackout Times Configure days and times during which the reclamation of virtual machine disk space do not take place.

To ensure that ESXi resources are dedicated to foreground tasks when necessary, you can prevent the ESXi hosts from performing these operations during specified periods of time on specified days.

For details, see " Set Storage Accelerator and Space Reclamation Blackout Times for View Composer Linked Clones" in the Setting Up Virtual Desktops in Horizon 7 document.

Transparent Page Sharing Scope

Select the level at which to allow transparent page sharing (TPS). The choices are Virtual Machine (the default), Farm, Pod, or Global. If you turn on TPS for all the machines in the farm, pod, or globally, the ESXi host eliminates redundant copies of memory pages that result if the machines use the same guest operating system or applications.

Page sharing happens on the ESXi host. For example, if you enable TPS at the farm level but the farm is spread across multiple ESXi hosts, only virtual machines on the same host and within the same farm will share pages. At the global level, all machines managed by Horizon 7 on the same ESXi host can share memory pages, regardless of which farm the machines reside in.

Note: The default setting is not to share memory pages among machines because TPS can pose a security risk. Research indicates that TPS could possibly be abused to gain unauthorized access to data in very limited configuration scenarios.
Domain Select the Active Directory domain and user name.

View Composer requires certain user privileges to farm. The domain and user account are used by Sysprep to customize the linked-clone machines.

You specify this user when you configure View Composer settings for vCenter Server. You can specify multiple domains and users when you configure View Composer settings. When you use the Add Farm wizard to create a farm, you must select one domain and user from the list.

For information about configuring View Composer, see the Horizon 7 Administration document.

AD container Provide the Active Directory container relative distinguished name.

For example: CN=Computers

When you run the Add Farm wizard, you can browse your Active Directory tree for the container.

Allow reuse of pre-existing computer accounts Select this setting to use existing computer accounts in Active Directory for linked clones that are provisioned by View Composer. This setting lets you control the computer accounts that are created in Active Directory.

When a linked clone is provisioned, if an existing AD computer account name matches the linked clone machine name, View Composer uses the existing computer account. Otherwise, a new computer account is created.

The existing computer accounts must be located in the Active Directory container that you specify with the Active Directory container setting.

When this setting is disabled, a new AD computer account is created when View Composer provisions a linked clone. This setting is disabled by default.

For details, see "Use Existing Active Directory Computer Accounts for Linked Clones" in the Setting Up Virtual Desktops in Horizon 7 document.

Use a customization specification (Sysprep) Provide a Sysprep customization specification to customize the virtual machines.