I shut down esxi host, disconnect it from SAN and after connecting on SAN and power on the few VMs were not in inventory and other VMs was disconnected?!
When I remove the host and add it again VMs were connected but still there was no that few VMs in inventory although I can browse datastore.
I bring it back manually, but why they was removed from inventory?
Then, maybe the DB had some problems (corrupted?). It's too hard for VI3 to loose at the same time vCenter, DB, and VMs.
In an Enterprise enviroment, VMware (or, at least, some VMware partners) recommend to place the DB outside the vCenter server (in our case, an external SQL2005 MSCS cluster).
All I can say is, add the VMs to Inventory again, and pray for not loosing SAN access again
VMs lost from the invetory do not neccesarily need to be indicative of SQL corruption.
When a host connects to a VC for the first time, the DB knows nothing about the VMs on it, but they exist in the inventory.
Do you have more than one Datastore, and did the ones that go missing all exist on the same Datastore?
If this is the case and the datastore was mapped under a differet guid, then the host would not have seen the VMs as available as it would look inthe wrong location.
When you rebooted, you probably got your SAN pathing back to what it was before and as such, the VMs re-appeared.
I have two datastores on that SAN, and as I can remember the missing VMs was on both of them. Also, on these datastores are VMs whose not disappeared. And there was no any important difference between VMs options regarding datastores.
VMs was not re-appeared after rebooting host, I must manually take them back with right click on .vmx file and "Add to inventory".