*BSD News Article 35161


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From: edward@priam.CS.Berkeley.EDU (Edward Wang)
Newsgroups: comp.os.386bsd.questions
Subject: Re: 512 or 1024K blocks?
Date: 30 Aug 1994 11:50:39 GMT
Organization: University of California, Berkeley
Lines: 20
Message-ID: <33v6ef$s1s@agate.berkeley.edu>
References: <33tp2tINN2j6@gambier.ugrad.cs.ubc.ca>
NNTP-Posting-Host: priam.cs.berkeley.edu
Cc: 

In article <33tp2tINN2j6@gambier.ugrad.cs.ubc.ca>,
Markus Meister <h5h1@ugrad.cs.ubc.ca> wrote:
>
>I may find myself installing FreeBSD again (to a different disk) and I
>remember the question whether your want a 512 or 1024K block file system, and
>it said that the 1024 kind takes more disk space but offfers more performance.
>Could someone either point me to a FAQ where this is mentioned, or post
>a note saying how much more disk space (typically) is used up and what
>kind of performance increase one could reasonably expect with the 1024k
>filesystem (I may well be not the only one wondering about that). I
>just want some very approximate figures.. I'd be gratefule for such insight.

I assume you mean 8k/1k vs. 4k/512 filesystems.
It's not at all clear that 4k/512 actually saves you space.
I ran some tests a few years ago, and it's really a toss up.
The reason is that 4k/512 filesystems have a greater chance
of needing indirect blocks.  It turns out that there are enough
files of intermediate sizes that 8k/1k wins pretty often.

I gathered the statistics on my own machine.  Your milage may differ.