Virtualised SQL Server Cluster test environment error "originally formatted with sector size 4096"

I am trying to set up an environment for testing a clustered SQL Server upgrade, so I have built a replica here on VMware Workstation 11.

I have provisioned 3 servers for this, two Windows Server 2012R2 for the SQL, and a FreeNAS 9.1 to provide the iSCSI shared volumes.

The iSCSI targets seem to work fine, the Failover Clustering setup accepts them for the cluster, and allows it's use for a Quorum volume.

The problem I have is that when I come to install a SQL Server instance onto the cluster, it gets as far as starting the databases up and then fails, with an error in the event log:

Master.mdf was originally formatted with sector size 4096 and is now on a volume with sector size 3072

That last number, 3072, varies on subsequent teardown/rebuilds, and I've seen it in the high 5-digits.

Any research on the error shows many results for issues with specific physical SAN drivers, or ancient results for products many years and versions behind.

Alternatively, is there a better way of bringing up a fully-virtualised SQL Cluster?