Re: Diskless boot: Anybody doing this big time?

From: James A. Crippen (james@UnLambda.COM)
Date: Sat Apr 28 2001 - 19:03:44 EST

On Sat, 28 Apr 2001, Karsten Jeppesen wrote:

> Anybody here booting more than 200 machines from the same server?
> If yes, then I would like to know something about your experience regarding
> boot time. There seems to be a lot of collisions, slowing things down.
> What would be the average boot time for such a network size given ... let's
> say 100Mb net and no other traffic but the boot?

The primary consideration is how many machines are booting in parallel and
how many are booting in serial fashion.

In serial fashion it's a simple calculation based on the average time for
a single boot, the bandwidth of the network, and the latency of the
network from boot server to booting client.

In parallel you'll have to account for the amount of bandwidth being used
by each client host and the latency increase incurred by the increased
bandwidth utilization.

And you have to consider the amount of resources consumed on the boot
server for each booting process and what its theoretical concurrent
maximum would be. This is dependent entirely on the performance and
design of the server and network.

Collisions aren't necessarily bad, but a large number of them are. That
may mean it's time to look into some network reconfiguration.


James A. Crippen <> ,-./-.  Anchorage, Alaska,
Lambda Unlimited: Recursion 'R' Us   |  |/  | USA, 61.2069 N, 149.766 W,
Y = \f.(\x.f(xx)) (\x.f(xx))         |  |\  | Earth, Sol System,
Y(F) = F(Y(F))                        \_,-_/  Milky Way.

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