Chapter 2. BIND Resource Requirements
DNS hardware requirements have
traditionally been quite modest.
For many installations, servers that have been retired from
active duty have performed admirably as DNS servers.
However, the DNSSEC features of BIND 9
may be quite
CPU-intensive, so organizations that make heavy use of these
features may wish to consider larger systems for these applications.
BIND 9 is fully multithreaded, allowing
full utilization of
multiprocessor systems for installations that need it.
CPU requirements for BIND 9 range from
i386-class machines,
for serving static zones without caching, to enterprise-class
machines to process many dynamic updates and DNSSEC-signed zones,
serving many thousands of queries per second.
Server memory must be sufficient to hold both the
cache and the zones loaded from disk. The max-cache-size
option can limit the amount of memory used by the cache,
at the expense of reducing cache hit rates and causing more DNS
traffic.
If additional section caching
(the section called “Additional Section Caching”) is enabled,
the max-acache-size option can be used to
limit the amount
of memory used by the mechanism.
It is still good practice to have enough memory to load
all zone and cache data into memory; unfortunately, the best
way
to determine this for a given installation is to watch the name server
in operation. After a few weeks, the server process should reach
a relatively stable size where entries are expiring from the cache as
fast as they are being inserted.
Name Server-Intensive Environment Issues
For name server-intensive environments, there are two
configurations that may be used. The first is one where clients and
any second-level internal name servers query a main name server, which
has enough memory to build a large cache; this approach minimizes
the bandwidth used by external name lookups. The second alternative
is to set up second-level internal name servers to make queries
independently.
In this configuration, none of the individual machines need to
have as much memory or CPU power as in the first alternative, but
this has the disadvantage of making many more external queries,
as none of the name servers share their cached data.
Supported Operating Systems
ISC BIND 9 compiles and runs on many
Unix-like operating systems and on
Microsoft Windows Server 2012 R2, 2016 and Windows 10.
For an up-to-date
list of supported systems, see the PLATFORMS.md file in the top-level
directory
of the BIND 9 source distribution.