Did you try to backup Hyper-V Virtual Machines with Windows Server backup and received Event ID 521 error on Hyper-V host? Backup started at '7.10.2008 23:21:14' failed as Volume Shadow copy operation failed for backup volumes with following error code...
Nick MacKechnie posted a great post about Hyper-V maximum supported configurations . Topics: Operating System Requirements Hardware Requirements Virtual Machine Architecture Support Memory Processors Networking Physical Storage Virtual Hard Disks Virtual...