Here is the beast.
I am evaluating unitrends appliance.
Mostly we are interested in VM backups.
I have a simple setup.
Vcenter appliance 5.5->esxi 5.1U1 host->VM
I register vcenter + esxi as clients in unitrends GUI.
Then start a 1 time VM backup of a small 6 gig linux VM.
Then I try to restore to the same vcenter->host but with different VM name.
The job start, and make the vcenter vpxd process crash with coredump, then this breaks vcenter connection to all clients that are using vcenter at that time.
I also tried with vcenter appliance 5.1, with the same results.
The only way I was able to restore, was to restore on a standalone esxi server that I removed from vcenter and registered as a direct client to the appliance.