I have 2 VM's v.10 that are unable to see/connect to a vmfs datastore on the host in the web client. The host is 5.5 and I have 2 other hosts and vm's that are 5.5/v.10 that can see the datastore fine and can see it in vcenter 5.5 fine. This is a utility datastore shared across hosts on which we keep ISO resources that was originally formatted on a 5.1 host.
Figured this out, the new web interface can be challenging at times. As the datastore was not already being accessed by the VM's it was not available by default from the CD menu. I had to go into edit settings of the VM and click the browse option to access the datastore. Once that had been done, it was visible via the CD menu.
remove the affected host and add it back to vcenter and check if you are getting the datastore back.
Figured this out, the new web interface can be challenging at times. As the datastore was not already being accessed by the VM's it was not available by default from the CD menu. I had to go into edit settings of the VM and click the browse option to access the datastore. Once that had been done, it was visible via the CD menu.