PVS Server High Availability
When dealing with highly available PVS environments, there are multiple components to consider. Firstly , PVS needs an SQL databases which somehow will need to be made HA, secondly , you will at least install and configure 2 PVS servers and enable HA within PVS software itself, which is done from management console and last , but not least , the storage where your vDisks reside also need to be shared or made HA. And of course, you can configure TFTP in HA too..
As a side note, multiple PVS servers can also be used for load balancing purposes with regards to the streaming traffic they handle – active /active.
When vDisks are stored locally on the PVS servers, you will need to implement some sort of replication mechanism so that all PVS server will be able to offer the exact same vdisks. This can also be done manually(copying) from PVS console . Recommended automation methods include both DFS-R and Robocopy.
When it comes to SQL Database, you have multiple options
- PVS offers a built-in offline database support mechanism. It uses a snapshot of the database when database becomes unavailable. By default, this feature is disabled.
- Database mirroring , SQL clustering and SQL Always ON are all valid options as well.
To conclude, here is a shortlist of components to consider when implementing HA for PVS
- The Provisioning Services SQL database
- Your physical or virtual provisioning servers.
- Storage used to store your vdisk files, PVS servers and/or target devices
- The TFTP servers for bootstrap delivery.
Once you have setup your basic provisioning Services infrastructure, you can use the streamed VM set-up wizard or the XenDesktop set-up Wizard to provision multiple virtual target devices
The Streamed VM set-up wizard
The wizard is accessed directly from the PVS management console and can create multiple virtual machines(Target devices) to where the vDisk will be streamed( a preconfigured template will be needed for this) it will create the target device in appropriate device collection and finally it will assign a vDisk in Standard Image Mode to the Virtual Machines.
During Wizard, you will be able to select Hypervisor to the VM template on which newly provisioned VM’s will be based and you need to select resources on subsequent wizards to create VM’s.
The XenDesktop set-up wizard
To be able to use the XenDesktop wizard ,you need to make sure that your Delivery Controller and Provisioning Servers are based on same version. The XenDesktop set-up wizard just as with the Streamed set-up wizard , created VM on a XenDesktop hosted Hypervisor(Host Connection) making use of a preconfigured template VM machine. does same .
It will also create target devices with in a new or existing device collections which will take the name of XenDesktop catalogue by assigning a Standard Image Mode vDisk to the VM’s and at the same time it will add virtual desktops in Machine catalogue within studio, this in a nutshell is what happened next:
- First, if needed, it will create a new XenDesktop Machine Catalog.
- Create VM’s on a host’s Hypervisor using the preconfigured machine template.
- Create BDM partitions, if specified.
- If using a Streamed with personal vDisk catalog, create a personal vDisk and then attach the personal vDisk to the VM.
- Create a write cache disk of the specified size.
- Create a Provisioning Services target devices, and then assign the selected vDisk to those devices.
- Add the target devices to the selected Provisioning Services Collection.
- Ass the VM’s to the XenDesktop Catalog.
- Boot each VM to format the newly created write cache disk.