We are using differencing disks for our RDP servers (basically VDI deployment). We have a three-node Hyper-V cluster utilizing SOFS cluster for VHDX storage. We have a service template that deploys the service. We are using VMM 2012 R2 with update rollup 2 (yes, we applied the SQL script after upgrading).
We create a new VHDX template about once a month (to incorporate patches into the build), which means that new services are created, and the parent disk gets copied from the templates into the parent location, and then new machines create their differencing disks from that parent.
It has been working splendidly for about six months, until last week when we attempted to deploy the latest VHDX and a new service that relies on it.
Even though each host in our cluster has a single "default parent disk path to be used for the virtual machines" configured to the SOFS share where we have our parent disks stored, the parent disk gets copied to a different share all together.
The place where the parent VHDX is going is in our list of available storage, but not in the "default parent disk path".
The share where it should be going has plenty of storage (200GB free) for the VHDX file (11GB). The hosts have access to the share, and it shows as OK in the VMM console.
Why is VMM choosing something other than what we specify? Why would it change this month, when it has been working fine for six months prior?