After some consternation trying to perform a simple PI server backup on my Windows 8.1 - x64 device I discovered I could perform a manual backup by unchecking the "Use VSS Backup" option on the dialog in the [Operation]=>[Backups] plugin of PI SMT. Apparently my Windows 8.1- x64 operating system is not compatible with VSS backups. So I am glad I was able to at least get a manual backup performed. Now I would like to set the pibackup.bat file or the task scheduler to do the same. So far I am unable to locate any instructions on how to do this. - I appreciate any feedback from the community of users who may have encountered this.
Also, when I perform a pibackup from the command line I also get the VSS backup errors. I don't know if there is an optional attribute I can write that will explicitly tell pibackup.bat to perform a non-VSS backup.
Worth noting is according to this tech support article: https://techsupport.osisoft.com/Troubleshooting/Alerts/AL00261 the VSS backup does not work on Windows Server 2012 R2 and one should use the non-VSS backup as an interim measure.