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List:       9fans
Subject:    Re: [9fans] a few (n)venti questions
From:       "Russ Cox" <rsc () swtch ! com>
Date:       2007-09-30 18:17:08
Message-ID: 20070930181711.D4DED1E8C3A () holo ! morphisms ! net
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> Since the installation CD has an issue with venti (or at least
> had a few days ago), I finally installed my CPU server without
> venti, with the plan of creating and adding venti later.  I am
> at the point of starting to format my venti partitions, but I
> have a few questions that I couldn't find answers to: I think
> I've got the arenas and datalog figured out, i will definitely
> need those, my question come to this new bloom filter.  I was
> wondering how much of a difference it made for let's say a 20-30
> gig datalog.  I only have 256MB of ram, so the issue is also:
> is it really worth it to give up 40-80MBs of ram (I haven't done
> the maths on it yet).

It's worth having a small one -- say 32MB -- just to make
the initial usage faster.  It helps a lot with fresh writes
at the beginning.  Once you've been using it for a while,
you might find that it's worth turning off, but it's easy to
just remove from the config (just don't put it back).

Only power-of-two sizes are used -- 32MB, 64MB, etc.

Russ

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