I just got a notification about this myself today. Apparently there is some interoperability issues with VAAI (vSphere APIs for Array Integration) & EMC RecoverPoint on EMC VNX arrays. It looks like the VNX Storage Processor (SP) may reboot with Operating Environment Release 32 P204 in a RecoverPoint environment.
EMC have just released today a technical advisory – ETA emc327099 – which describes the issue in more detail but is basically advising customers to disable VAAI on all ESXi hosts in the RecoverPoint environment while they figure this out. Hopefully it won’t take too long to come up with a solution to allow VAAI run in these environments once again.