When VSC tries to take backups of my ESX datastores, it chokes on trying to snapshot running sims: takes 15 mins to give up, and ends up tossing alerts. (keyword bingo: msg.snapshot.error-QUIESCINGERROR )
Hacky/not-formally-doc'ed workaround suggested: Mark the disks as "Independent Persistent".
Quote from Support:
"The vSIM does not have a filesystem driver available to perform a flush. To do so, we would have to re-code ONTAP to recognize that there is a request coming into the "controller" asking for us to flush the filesystem to disk. When SMVI (or any other backup software) requests a "VMware quiesced snapshot", it sends the request to quiesce the filesystem, but does not flush memory. This is why [...] the SMVI quiescing is failing when you're trying to do it during a backup operation."
RFE: put some real tools in vsims so the interaction between vsims and backups is less silly.