I have a Scale-Out File Server (SOFS) acting as the storage for one of my test Hyper-V server. All servers involved are running Windows Server 2012 R2 Update 1.
I'm noticing that when I copy a bunch of large files (several .iso images) directory to the SOFS's share (i.e.\\SOFS\share1), I get great and steady performance of about 90-100 MB/s (limit of my current 1 GbE connection).
The problem is when I copy the same .iso images to a VM's hard drive that is running on the SOFS's share (i.e. copy to\\VM1\D$ which is actually \\SOFS\Share1\DriveD.vhdx), I get really slow and very unsteady performance ranging from 10 MB/s to 50 MB/s (mostly at the lower end).
Reading from the SOFS, either directly or through the VM, gets awesome performance and is not an issue. Only when writing to the VM on the SOFS.
I'm thinking the VM itself is the bottleneck. Any suggestions on improving the disk write performance in the VM?
Thanks