Start-AzureStorageBlobCopy error in Automation runbook - powershell

Question

I'm following this guide to automate backups of Linux VMs in Azure Automation. Everything goes well in testing on initial run, but the second and all subsequent tests return the following error:
11/26/2014 11:03:45 AM, Error: Start-AzureStorageBlobCopy : One or more errors occurred.
At LinuxVMBackup:40 char:40
+
+ CategoryInfo : CloseError: (:) [Start-AzureStorageBlobCopy], AggregateException
+ FullyQualifiedErrorId :
AggregateException,Microsoft.WindowsAzure.Commands.Storage.Blob.Cmdlet.StartAzureStorageBlobCopy
Here is the runbook:
workflow LinuxVMBackup
{
param (
[Parameter(Mandatory=$true)]
[PSCredential]
$Cred,
[Parameter(Mandatory=$true)]
[string]
$subName,
[Parameter(Mandatory=$true)]
[string]
$serviceName,
[Parameter(Mandatory=$true)]
[string]
$vmName
)
# Login and get VM
$null = Add-AzureAccount -Credential $Cred
$null = Select-AzureSubscription -SubscriptionName $subName
$vm = Get-AzureVM -ServiceName $serviceName -Name $vmName
# Stop VM
$vm | Stop-AzureVM -StayProvisioned
# Get OS and Data Disks
$vmOSDisk = Get-AzureOSDisk -VM (Get-AzureVM -ServiceName $serviceName -Name $vmName)
$vmDataDisks = Get-AzureDataDisk -VM (Get-AzureVM -ServiceName $serviceName -Name $vmName)
# Get and set storage name
$StorageAccountName = $vmOSDisk.MediaLink.Host.Split('.')[0]
Set-AzureSubscription -CurrentStorageAccount $StorageAccountName -SubscriptionName $subName
$backupContainerName = "backups"
if (!(Get-AzureStorageContainer -Name $backupContainerName -ErrorAction SilentlyContinue)) {
New-AzureStorageContainer -Name $backupContainerName -Permission Off
}
# Snapshot OS Disk
$vmOSBlobName = $vmOSDisk.MediaLink.Segments[-1]
$vmOSContainerName = $vmOSDisk.MediaLink.Segments[-2].Split('/')[0]
#Error on this line
Start-AzureStorageBlobCopy -SrcContainer $vmOSContainerName -SrcBlob $vmOSBlobName -DestContainer $backupContainerName
#Error on this line
Get-AzureStorageBlobCopyState -Container $backupContainerName -Blob $vmOSBlobName -WaitForComplete
#Snapshot Data Disks
ForEach ($vmDataDisk in $vmDataDisks) {
$vmDataBlobName = $vmDataDisk.MediaLink.Segments[-1]
$vmDataContainerName = $vmDataDisk.MediaLink.Segments[-2].Split('/')[0]
Start-AzureStorageBlobCopy -SrcContainer $vmDataContainerName -SrcBlob $vmDataBlobName -DestContainer $backupContainerName -Force
Get-AzureStorageBlobCopyState -Container $backupContainerName -Blob $vmDataBlobName -WaitForComplete
}
#Get blobs in storage and output
$insertedBlobs = Get-AzureStorageBlob -Container $backupContainerName
Write-Output $insertedBlobs
$vm | Start-AzureVM
}
I couldn't find anything online, save an answer on Microsoft forums for a similar error stating that the VM needs to be stopped, so I thought maybe the VM is not fully stopped when Start-AzureStorageBlobCopy is initiated. I tried testing with a stopped VM and still got the error.
Thanks for your help.

Answer 1

Given the error only happens after the first successful copy, what is probably happening is the Start-AzureStorageBlobCopy cmdlet is trying to request user confirmation for the operation, since it would overwrite existing data. Since Azure Automation runs runbooks in a non-interactive session, user confirmation cannot be asked, so the command is failing.
Adding -Force should "force" user confirmation for the cmdlet and fix the issue. You have this parameter on the second instance of Start-AzureStorageBlobCopy, but not the first.
PS - You should put this runbook in our runbook gallery so others can take advantage of it!