About Neverfail for Hyper-V
Neverfail for Hyper-V Plug-in provides protection proactive
monitoring for Microsoft Hyper-V Server environment’s configuration data,
services, and application data files.
Neverfail for Hyper-V Plug-in automatically detects the Hyper-V
role installed on the Windows server and protects its associated services, configuration,
as well as all the managed VMs hard drive files (vhd(x), avhd(x)), configuration
files, and snapshots stored locally on the server.
- Microsoft Hyper-V Server Role
installed on standalone (non-clustered):
Server 2019 Standard and Datacenter (Desktop Experience)
Server 2016 Standard and Datacenter (Desktop Experience)
Neverfail for Hyper-V Plug-in
monitoring consists of the following:
- Service Availability Monitoring
- Application Monitoring
- Protected Data Monitoring and Replication
Neverfail Continuity Engine monitors services specified by
the plug-ins to ensure application availability. In the event a specified
service stops or fails, Continuity Engine can take up to three
pre-configured actions to remedy the issue.
the plug-in is being installed, all the protected services will be set to Manual
startup type, unless otherwise stated.
This is the
list of all services protected by this plug-in:
- Hyper-V Virtual Machine Management - Automatic/Running (default)
- Hyper-V Host Compute Service - Automatic/Running (default)
- Hyper-V Data Exchange Service - Manual/Stopped (default)
- Hyper-V Guest Service Interface - Manual/Stopped (default)
- Hyper-V Guest Shutdown Service - Manual/Stopped (default)
- Hyper-V Heartbeat Service - Manual/Stopped (default)
- Hyper-V PowerShell Direct Service - Manual/Stopped (default)
- Hyper-V Remote Desktop Virtualization Service - Manual/Stopped (default)
- Hyper-V Time Synchronization Service - Manual/Stopped (default)
- Hyper-V Volume Shadow Copy Requestor - Manual/Stopped (default)
- Tasks - The
following 'Tasks' are installed by Neverfail for Hyper-V Plug-in:
- Pre Stop
- Post Start
Hyper-V Pre Stop task
Triggers a powerShell cmdlet that stops all the managed Hyper-V VMs. This task is
triggered before Hyper-V service has been successfully stopped, and is
intended to run before the protected application services are gracefully
stopped, when switching the active server (during a switchover).
Hyper-V Post Start task
Triggers a powerShell cmdlet that starts all the Hyper-V VMs. This task is
triggered after Hyper-V service has been successfully started, and is intended
to run after the protected applications are gracefully started, when switching
the active server (during a switchover or failover).
To configure/modify Periodic 'Tasks', follow the steps
- Using the Neverfail Continuity
Engine Management Service UI, go to Protected Server -> Tasks
- Edit the desired 'Task'.
- Configure/modify the 'Interval'
- Click OK to
save the changes.
Note: 'Interval' is the only field available for configuration/modification
and is measured in seconds. Note: One can also Enable/Disable the selected 'Task' (it is
recommended to leave it Enabled)
Data Monitoring and Replication
When the Neverfail for Hyper-V Plug-in is being installed,
it detects the Hyper-V feature configuration data files, registries,
application and user data associated with the Hyper-V server as well as all the managed VMs hard drive files (vhd(x), avhd(x)). These data
items will be detected then added to the protected set by the plug-in's
automatic filter discovery mechanism (their contents will be synchronized, and
subsequent updates replicated to the passive server).
The plugin's filter discovery mechanism automatically detects and includes in data protected set only the in-use VMs virtual disk file which may be the vhd(x) (virtual disk files) or avhd(x) (snapshot files). This is intended to be a replication optimization: i.e. the protected data set is dynamically updated to contain just the disk files which are subject to changes. All the other disk files not being in use should be already replicated on the passive nodes either via hosts' initial cloning (for files being created and not in use at the time Engine standby node was added) or via the replication mechanism (for disk files being in use at a previous moment, when Engine replication was on).
Installing the Neverfail for Hyper-V Plug-in
This is done automatically during Continuity Engine
deployment driven from Engine Management Service if the Microsoft Hyper-V
Server Role is detected as being installed on the target server.
- Current design of Hyper-V Plugin
defines Pre Stop and Post Start tasks which are starting/stopping all the
managed Hyper-V VMs. More granular VM start/stop control can be achieved through
user defined tasks (edited post-installation).
- Replication issues (Out of
sync) are encountered when new VMs or VM Checkpoints are created from
Hyper-V Manager: Automated Out Of Sync : Use of :
Extended Attributes , has been detected for : *.vmcx and *.VMRS files. Workarounds:
- (1) Manually triggering synchronize on the OOS files will put the server again
- (2) Disable the Extended Attributes unsupported features as
suggested in How to Disable the Extended Attributes
for Hyper-V Plug-in v201.5.1