Certain Verba server roles run real-time media applications, and as such requires low-latency access to resources to perform according to specification and to sizing guidelines. This document provides an overview of the recommendations for provisioning the servers in a Hyper-V environment. Failure to follow the configuration recommendations provided can result in the loss of recording, application functionality, and data loss.

Version support

Supported virtualization environments for the server-side are listed.

Windows Server 2012 R2 Hyper-V
Windows Server 2016 Hyper-V
Windows Server 2019 Hyper-V

Recommendations

The following table lists the recommendations for Hyper-V deployments for the specific server roles:

	Recommendation	Applicable Server Roles
Memory	Set 100% memory reservation. Reserving physical RAM on the VM guest prevents memory ballooning from occurring. If memory ballooning does occur, due to insufficient physical RAM, delays and recording loss can occur due to memory swapping.	Recording Server Media Collector and Proxy Server Announcement Server
Memory	Set with the appropriate size in GBs (defined in the sizing guide according to server role)	All
CPU	Reserve 100% of the CPU, which guarantees exclusive pCPU access, which in turn helps to reduce vCPU halt/wake-up cost	Recording Server Media Collector and Proxy Server Announcement Server
	Configure the appropriate number of vCPUs (defined in the sizing guide according to server role)	All
	The physical host must have extra processing available for scheduling, network handling, device interrupt handling, and other related tasks. To prevent any loss of recording, do not over-commit the CPUs on a host. The equivalent of two physical CPU core must be available to handle these tasks.	All
Disk	Disk subsystem should be correctly sized based on the required capacity and performance	Recording Server
Network	Enable promiscuous mode on the virtual interface when network port mirroring (passive) recording is used	Recording Server Media Collector and Proxy Server
Network	Enable Receiver Side Scaling (RSS) for high-performance network settings. Network driver configuration settings: Maximum number of RSS processors: number of cores Maximum number of RSS queues: number of cores Receive Side Scaling: enabled Receive buffer size: 32 Mbyte Send buffer size: 32 Mbyte	Recording Server Media Collector and Proxy Server Announcement Server
Other	Do not use snapshotting in business hours, because snapshotting causes the VM host to pause execution on virtual machines. Sometimes, all virtual machines on the host are paused. Use of snapshotting during business hours can result in recording loss.	Recording Server Media Collector and Proxy Server Announcement Server

If the required CPU and memory resources are not available for the VMs, problems will manifest during high-stress periods. During high-stress periods, use of system resources in real-time rapidly increases. Reserving the required resources ensures the integrity of the system and its performance at the stated level in all conditions. When reservations are not set correctly, the following problems can occur:

Excessive packet drops can lead to data loss
Shared memory and memory ballooning can cause recording loss because memory is used by other virtual machines and is not instantly available
Shared CPUs can cause recording and packet loss when sudden surges of network activity require more processing power
Incorrectly sized disk subsystems cause recording loss when shared by multiple applications.

Additional information

The following documents from Microsoft discuss how to plan and optimize Hyper-V: