Azure backup Start-OBBackup does not reliably emit errors

I noticed that the Windows Azure Online backup command does not always emit an error when the backup does not successfully complete in say a Try / Catch block.

This was most apparent when the job was cancelled/failed at an early stage during the backup.

As such it is easier to look through the output of the backup command and make sure it contains the text "The backup operation completed successfully". The output only contains this string if the backup completes successfully.

eg

$SuccessString = "The backup operation completed successfully"

$OnlineBackupOutput = Get-OBPolicy | Start-OBBackup
$OnlineBackupOutputString = $OnlineBackupOutput | Out-String

Then you can check
if ($OnlineBackupOutputString -match $SuccessString)
# ok
else
error condition...