Re: [9fans] Venti arenas and index guidelines

["Russ Cox" <rsc@swtch.com>]

> I have a fossil on an 18G hard drive, which from what I've seen, is
> probably a much larger fossil than I need. However, I wasn't planning
> on changing it unless it's really trivially easy to do so. I also have
> another 18G drive and two 50G drives. I thought the thing to do would
> be to mirror the 50G drives for venti arenas and that would leave the
> 18G drive for isects (and bloom?).

Venti is much less sensitive to disk seek times than it once was.
(See http://swtch.com/~rsc/papers/fndn/ and s/Foundation/Venti/g.)
So to a first approximation, it basically doesn't matter what you do.

Mirroring is a good idea; that's a good argument for putting the
data on the 50G pair.  You could also put the isect and bloom filter
there, to keep the setup simple.  You only need 5% = 2.5G for
index; 18G is overkill.  The bloom filter helps most when you are
first initializing the venti, and for that it can be small (64MB is
probably plenty).

Russ