1.. Copyright (C) Internet Systems Consortium, Inc. ("ISC") 2.. 3.. SPDX-License-Identifier: MPL-2.0 4.. 5.. This Source Code Form is subject to the terms of the Mozilla Public 6.. License, v. 2.0. If a copy of the MPL was not distributed with this 7.. file, you can obtain one at https://mozilla.org/MPL/2.0/. 8.. 9.. See the COPYRIGHT file distributed with this work for additional 10.. information regarding copyright ownership. 11 12.. _requirements: 13 14Resource Requirements 15===================== 16 17.. _hw_req: 18 19Hardware Requirements 20--------------------- 21 22DNS hardware requirements have traditionally been quite modest. For many 23installations, servers that have been retired from active duty 24have performed admirably as DNS servers. 25 26However, the DNSSEC features of BIND 9 may be quite CPU-intensive, 27so organizations that make heavy use of these features may wish 28to consider larger systems for these applications. BIND 9 is fully 29multithreaded, allowing full utilization of multiprocessor systems for 30installations that need it. 31 32.. _cpu_req: 33 34CPU Requirements 35---------------- 36 37CPU requirements for BIND 9 range from i386-class machines, for serving 38static zones without caching, to enterprise-class machines 39to process many dynamic updates and DNSSEC-signed zones, serving 40many thousands of queries per second. 41 42.. _mem_req: 43 44Memory Requirements 45------------------- 46 47Server memory must be sufficient to hold both the cache and the 48zones loaded from disk. The :any:`max-cache-size` option can 49limit the amount of memory used by the cache, at the expense of reducing 50cache hit rates and causing more DNS traffic. It is still good practice 51to have enough memory to load all zone and cache data into memory; 52unfortunately, the best way to determine this for a given installation 53is to watch the name server in operation. After a few weeks, the server 54process should reach a relatively stable size where entries are expiring 55from the cache as fast as they are being inserted. 56 57.. _intensive_env: 58 59Name Server-Intensive Environment Issues 60---------------------------------------- 61 62For name server-intensive environments, there are two 63configurations that may be used. The first is one where clients and any 64second-level internal name servers query the main name server, which has 65enough memory to build a large cache; this approach minimizes the 66bandwidth used by external name lookups. The second alternative is to 67set up second-level internal name servers to make queries independently. 68In this configuration, none of the individual machines need to have as 69much memory or CPU power as in the first alternative, but this has the 70disadvantage of making many more external queries, as none of the name 71servers share their cached data. 72 73