server sizing

[Mathias Körber]

One of the questions you ask yourself for this is whether the server
is intended as a resolving/caching nameserver for local clients =
(workstations,
other servers) to use, or whether it is supposed to be authoritative for =
your
own zones, (and how many), or a mix of both.

If the server is solely authoritative (primary and/or secondary), the =
memory
usage will not increase much after initial load, as all zones will have =
been loaded
into memory at start/reload. In this case the memory usage really =
depends
on the number and size of zones you serve, but is relatively easy to =
determine:
Load all zones and look at he process size, then put in at least that =
much RAM, making
sure you leave sufficent RAM for other processes etc...

If the server is going to be a busy caching server (eg for a large ISP), =
you will
require LOTS of RAM (several hundred MB to a few GB).=20

If it served a smaller community, you may get by with 128MB RAM for =
this, unless your
small community has a wild variety of tastes and as such accesses many =
different sites...

A mixed server would need sufficient RAM for the zones it itself serves, =
plus a healthy
overhead for cached data, so just add that up according to the above.


As for CPU, nameservers are not very CPU hungry, and you could get by =
with a moderate
Pentium II or a low-end PIII. Faster CPU these days is not very =
expensive though, and it
does ot pay to try and save a few bucks on this.. CPU speed (and thst of =
the storage subsystem) can
noticeably influence the reloading time if you have many zones, so for a =
large nameserver
I'd choose a fast (but not bleeding edge) CPU and a good fast SCSI =
(Ultra2-LVD or 160)
controller and disk(s).

Finally, disk. Nameservers do not require much diskspace themselves, =
just sufficient to
store the zone-files, statictics and logfiles on. If you are running a =
busy caching nameserver
and keep query-logs, these can get large (Gigabytes per day), but else a =
medium sized disk
(9.1GB seems to be the norm these days for SCSI) should be able to hold =
the O/S, software
and all the required data...

Hope this helps

> -----Original Message-----
> From: bind-users-bounce at isc.org [mailto:bind-users-bounce at isc.org]On
> Behalf Of Yoko Ishizuki
> Sent: Monday, September 18, 2000 4:24 PM
> To: bind-users at isc.org
> Subject: server sizing
>=20
>=20
>=20
> I'm estimating a server size for a DNS server.  I need to determine =
its
> CPU, memory, and disk size.  I have searched for the web for =
information
> concerning this, especially for memory size needed and sessions BIND
> accepts at a time, but I couldn't.  I heard that BIND goes on =
increasing
> its memory use until restarted.  I expect our DNS server will be
> accessed quite often.
>=20
> Could anyone tell me how you have estimated your DNS server hardware?
>=20
> --
> Yoko Ishizuki
>=20
>=20
>=20