On Tue, Oct 8, 2013 at 3:41 PM, Arnold Schekkerman <[email protected]> wrote: > Hi Ryan, > What is the advantage of off-host servers? why not use the host as (single) > time-source for all virtual client machines?
The security policy of most production virutalization environment's I've seen explicitly prevents the VMs from talking to the host server at all via the network. They're usually on separate VLANs with whatever ACLs/firewalls in-between. If you don't have those same sort of security requirements, what you describe sounds efficient. A second potential problem is that VMs *move* between hosts while they're live and running. So you never really know which physical host you're going to be on, so you don't know which server to talk to. Something like VMware DRS moves servers all the time, and even shuts down hosts automatically at night to save electricity. So you would need some sort of isolated network with the same IP range configured in each VM and on each host. Ugly. Or maybe multicast clients with the hosts acting as multicast servers. There is always the "time sync" option in the VM tools packages for various hypervisors, but that doesn't seem to work as well as running NTPd or the Windows Time Service inside the VM in my experience. -- RPM _______________________________________________ pool mailing list [email protected] http://lists.ntp.org/listinfo/pool
