I have a standalone Hyper-V hosts (2012 R2) with a couple of VM running on NetApp LUNs. I have a separate LUN for each VM. I've configured a backup using the SnapProtect Hyper-V iDA. However, when I run the backup, I get the following error:
The writer experienced a non-transient error. If the backup process is retried, the error is likely to reoccur.
When logged in to the Hyper-V hosts, running vssadmin list writers shows that the Hyper-V vss writer is in error state:
Hyper-V on server 2012 R2 doesn't seem to like VM disks (vhds) stored in the root of the drive (e.g. in D:\vm.vhd). Doing this results in the stated error. Instead, create a folder, and move the vhd into the folder (e.g. D:\vm\vm.vhd). Then the error clears and backups are successful.