Guidelines for Sever dimensioning

[Simon Hobson]

T Manikandan-Q3926C wrote:

>Can anybody help me in dimensioning the DHCP server?

Try the archives - it's been discussed a few times !

>I Have X number of clients to be supported by the server. How will I 
>obtain the CPU, RAM and Hard disk calculations?

Sorry, but you can't. There are just too many variables to say X 
clients need Y hardware.

How long are your leases ? Minutes, Hours, Days, Weeks - longer 
leases put less load on DHCP server.

What mix of clients do you have ? Some (Windows) send loads of DHCP 
Informs which add extra load. Some (most printers, Mac OS X) don't 
retain a lease across restarts so NEED the DHCP server to come alive 
when switched on in the morning). Some clients (Windows) will quite 
happily keep their existing lease and start up on the same network 
with the old address if they can't contact the DHCP server.

What pattern of use do your clients have ? A rigid working 
environment where several thousand PCs all get switched on between 
8:20 and 8:30 is very different from one where they get switched on 
at random times as people come and go on flexitime. We once had a 
query from someone considering (IIRC) something like 50,000 clients 
and bothered about a statewide power outage - and all 50,000 clients 
wanting an address at the same time.


 From previous discussions, it would seem that a significant 
constraint is disk performance. You can minimise this by various 
techniques - in extreme putting your lease file on a solid state disk 
(eg battery backed ram disk). Network load is unlikely to be a 
constraint, and normally CPU loading isn't a problem either.