Avamar Hyper-V VSS plug-in: Config and Install of Latest Cumulative HFs for 19.4 and later

Summary: Read how to install or upgrade the latest Hyper-V plug-in cumulative hotfix (HF), and configure the Microsoft "SharedStoragePath" parameter required for Resilient Change Tracking (RCT) backups. This article applies to RCT Hyper-V backups for Windows 2016 and 2019 and 2022. ...

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Instructions

Introduction:

The Avamar Hyper-V plug-in cumulative hotfixes are required for the Hyper-V backups. They are especially important for Resilient Change Tracking (RCT) backup types and include code fixes and performance improvements.

List of Hyper-V plug-in's latest cumulative hotfixes:

  • Avamar Plugin version 19.4.100-124 HF 337285
  • Avamar Plugin version 19.7.100-82 HF 338739
  • Avamar Plugin version 19.8.100-83 HF 338731
  • Avamar Plugin version 19.9.100-78 HF 338821
  • Avamar Plugin version 19.10.100-135 HF 338820
Note: For Avamar Hyper-V plug-in version 19.4.100-116 or earlier, upgrade to version 19.4.100-124 or later and apply the corresponding hotfix.

To download the hotfixes, see the section Looking for a Hotfix knowing the HF number in the article Avamar: How to find and download a product hotfix, patch, install or upgrade package from the Dell Support website 

These instructions are a two-steps process to be followed in order:
  1. Hyper-V environment configuration and clean-up requirements 
  2. Installation of the Hyper-V plug-in cumulative hotfixes


Step-One:

  • Hyper-V environment configuration and clean-up requirements 
These prerequisites must be checked and fulfilled before installing the Hyper-V plug-in cumulative hotfixes.
  • The Avamar Hyper-V Plugin must be at version 19.4.100-124 or later (if using a previous version, upgrade to 19.4.100-124 or later).
  • The Windows operating system on each Hyper-V node must be running on Server 2016, 2019, or 2022.
  • In the environment, there should not be stale VM groups or Recovery Checkpoints on any cluster nodes.
  • The Hyper-V Cluster Shared Storage Path parameter should be configured to reference a <CSV or SMB> location. The path is case-sensitive, be exact in entering the value in the steps below.
Here are the three possible scenarios and related steps to follow:
  • A) If this parameter was never set:
And Hyper-V backups with Avamar were already run, the backup log shows the following messages. This means that the environment change is required. Without this change, the hotfix does not work: 
2022-03-24 13:24:38 avhypervvss Info <0000>: Calling Thread identity: NT AUTHORITY\SYSTEM
2022-03-24 13:24:38 avhypervvss Info <0000>: SharedStoragePath is not set
2022-03-24 13:24:38 avhypervvss Info <0000>: Exception in GetTargetVMsForRCT Failed to validate shared storage path
  • B) If this parameter was already set:
Use the following PowerShell command (as Administrator) to validate that it was set correctly: 
Get-VMHostCluster -ClusterName <<cluster name>>
Example: 
Get-VMHostCluster -ClusterName DELLHYPERV
The path presented for the Cluster Shared Storage Path should be a path on a CSV or SMB storage. 
 
If the path is not set correctly, and you would proceed with the HF installation, the Avamar Hyper-V plug-in detects it while backing up. It stops the backup process.
 
In such cases, discuss the Hyper-V configuration with the Hyper-V Administrator.
  • C) If you must set this parameter:
Caution: This is a one-time change during the lifetime of the Hyper-V cluster, it must be carefully planned and set on a CSV or SMV shared storage accessible to all nodes.
  • If unsure consult it with your Hyper-V Administrator before proceeding with the next step.
  • The path is case-sensitive, be exact in entering the value in the steps below.
  • In order to set the Cluster Shared Storage Path parameter, create a shared CSV folder first which should be a subdirectory (not root path) of the CSV or SMB.
  • If your Hyper-V administrator has confirmed it, run the following command in PowerShell (as Administrator) to set the Shared Storage Path parameter:
Set-VMHostCluster -clustername <<cluster name>> -SharedStoragePath <CSV>
Example: 
Set-VMHostCluster -clustername DELLHYPERV -SharedStoragePath C:\ClusterStorage\Volume1\Shared-RCT
To validate the Shared Storage Path that you set, run the following command (as Administrator) 
Get-VMHostCluster -ClusterName <<cluster name>>
  • Other general requirements for a healthy environment:
As per Microsoft best practices, and for a successful backup:
  • Checkpoint issues can occur if the Integration Services for the virtual machines are either not enabled, not running, or not initialized.
    • Check that Hyper-V Integration Services are up to date and running inside the virtual machines.
    • Check the status of the VSS writers of failed guest VMs using the command regular:
vssadmin list writers
  • If there are errors, restart the VSS service and check the status again (it must be stable)
  • Sometimes a system reboot may be the only option to clear the VSS writer errors.
  • Ensure that Hyper-V Hosts and VM guest operating system are at the latest patches.


Step-Two:

  • Installation of the Hyper-V plug-in cumulative hotfix:
    • Once downloaded, the README.txt file is found with the hotfix files.
    • In the README.txt file under the section Save and Backout instructions, you find the exact steps to correctly apply hotfix.
    • The recommendation is to carefully read those steps before trying to install the hotfix.

Additional Information

Note: Comments about the backup performance speed after applying either of the following hotfixes:
  • Avamar Plugin version 19.4.100-124 HF 337285
  • Avamar Plugin version 19.7.100-82 HF 338739
  • Avamar Plugin version 19.8.100-83 HF 338731
  • Avamar Plugin version 19.9.100-78 HF 338821
  • Avamar Plugin version 19.10.100-135 HF 338820
An RCT backup takes longer to complete after applying the cumulative hotfix. This is expected behavior.

Affected Products

Avamar
Article Properties
Article Number: 000211510
Article Type: How To
Last Modified: 21 Nov 2024
Version:  10
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