Bind9 on VMWare

[John Wobus]

Re vmware, I’m definitely interested in anything folks
have discovered about udp performance issues but I have
no negative experience to offer.  We mix vmware and hardware,
but have both auth and query servers on both.  Load tests
didn’t reveal any issues that made us reconsider.

We had an interesting time when we migrated a DNS server that
doubled as our central ntp server into vmware.
Later we moved the ntp server back to bare metal somewhere.
But the issue was not udp; it was the virtualized “hardware” clock.

I have a personal concern about dependencies, e.g. if you ever have
to deal with a problem that’s taken a whole vmware cluster
down.  If the infrastructure or the folks attempting
to fix the infrastructure depend on dns,
or even if they merely work more efficiently when dns is there,
then having that huge single point of failure that takes down
dns could have costs.  Same for a lot of low-level services.
Overall architectures can take this into account.

John Wobus
Cornell University IT