So I had to remotely shut down my servers last night as the air conditioner crapped out on us. I shut down the VMs and then the hosts. Fired up the 2 hosts today which auto start the VMs. Datastores for the VMs are isci LUNs located on a Synology NAS that we have, the NAS was not shutdown. For some reason when I booted everything back up my email VM shows as inaccessible and I am getting all sorts of errors in the logs saying "ATS-ONLY VMFS volume 'Synology-Email server' not mounted. Host does not support ATS or ATS initialization has failed" all of my other VMs are perfectly fine with other datastores on the same NAS.
When browsing to the datastore in Vsphere client or vcenter then I cannot mount, unmount or browse files as they are all greyed out. I have tried restarting both the host and the NAS a few times.
ESXi 6.0 on both hosts