Return
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Title
How to work around failed Hyper-V exports due to vnic limit -
Description
You are running AppAssure 5.4.2.x patched with P-001008.You notice that, depending on the number of vnics on the protected machine, the export is going to fail after a few successful exports. This happens because a new set of vnics is added with each export. Once 8 vnics are added to the VM the export fails due to Hyper-V VM virtual hardware limitations. Next export is going to be successful but it will be a full image export -
Cause
The issue is caused by defect D-23815 was not included with P-1008 (but was previously addressed in P-000976). The solution used in P-000976 was to do the virtual harware configuration only once, during the first export and skipping it on the subsequent ones, thus not reflecting any virtual hardware changes on the live machine after the initial export.NOTE: D-23815: New Ethernet adapter instance is added to the exported VM during the every continuous Hyper-V export job. -
Resolution
A powershell script to be performed before each export has been prepared. The script must be called PreExportScript.ps1 and needs to be dropped in the C:\ProgramData\AppRecovery\Scripts folder (which is the default location). If the folder does not exist, it has to be created.If running the script with parameters is desired, please do the following (you may want to use names and paths that make sense to your environment):1. rename the script provided PreExportScript.ps1 to vnics.ps12. copy the script to c:\temp3. create a file called PreExportScript.ps1 in C:\ProgramData\AppRecovery\Scripts4. add the following content using only the parameters that apply:powershell c:\temp\nics.vnics.ps1 -hypervhost <your hyperv server> -logpath <your log path> -vmcheck <machine1>,<machine2>5. run the script manually to make sure that it works as intended.The script has the following parameters:logpath -- by default c:\temp\nics-<date-time>hypervhost -- by default local core namevmcheck -- default the list of standby Hyper-V VMs (other types, i.e. Esxi, are excluded)The provided script is fully documented.Runningget-help PreExportScript.ps1 -fullwill show the complete documentationIt is recommended to run the script manually to check if it is running as expected.The script code is shown below between horizontal lines and attached to the KB.______________________________________________________________________<#.SynopsisDeletes all vnics on a Hyper-V virtual standby before a new export takes place thus working around the 8 vnics limit.DescriptionScript tested on Hyper-V 2012R2. Make sure that the Hyper-V Powershell module is installed.Drop the script into C:\ProgramData\AppRecovery\Scripts\PreExportScript.ps1.Parameter logpathdefault c:\temp\nics-<date-time>.Parameter hypervhostdefault local core name.Parameter vmcheckdefault the list of standby Hyper-V VMs (other types, i.e. Esxi, are excluded).Examplepreexportscript.ps1.Examplepreexportscript.ps1 -hypervhost machine1 -vmcheck machine2,machine3#>param ($logpath = "c:\temp\nics-$((get-date).ToString(`"yyyy-MM-dd-HH-mm-ss`")).txt",$hypervhost=($env:computername),[array]$vmcheck=((Get-VirtualizedServers | where {$_.LocationDisplayExportTypeName -eq "Hyper-V"}).agentdisplayname))#filter Out-Default{ $_ | Out-File 'C:\logfile.txt' -append }Write-Host "`r`nStarting pre-export vnic removal script...`r`nHyper-V host: $hypervhost`r`nList of machines to check:"; $vmcheck | ft$vm = get-vm -ComputerName $hypervhost$Title = "Virtual Machines on Hyper-V Host $hypervhost"$Title$title >$logpath$vm >> $logpathforeach($singlevm in $vm){$vmachine = $singlevm.nameif ($vmcheck -contains $vmachine){$nics = Get-VMNetworkAdapter -VMName $vmachine -ComputerName $hypervhost$nics | ft$nics | ft >> $logpath$result = Remove-VMNetworkAdapter -Name "*" -VMName $vmachine -ComputerName $hypervhost$result$result >> $logpath}}#dir function:\Out-Default | del______________________________________________________________________Product: AppAssure 5.4.2.192 with P-001008 only. -
Defect ID
131780