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To: Eric Anderson <anderson@centtech.com>
From: "Poul-Henning Kamp" <phk@phk.freebsd.dk>
In-Reply-To: Your message of "Wed, 03 Sep 2003 15:30:40 CDT."
             <3F564F70.1000905@centtech.com> 
Date: Wed, 03 Sep 2003 22:34:16 +0200
Message-ID: <64560.1062621256@critter.freebsd.dk>
cc: freebsd-performance@freebsd.org
cc: Petri Helenius <pete@he.iki.fi>
Subject: Re: 20TB Storage System 
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In message <3F564F70.1000905@centtech.com>, Eric Anderson writes:
>Poul-Henning Kamp wrote:
>> In message <3F564DF6.3090200@he.iki.fi>, Petri Helenius writes:
>> 
>> 
>>>You have any insight into the fsck memory consumption? I remember getting
>>>myself saved quite a long time ago by reducing the number of inodes.
>> 
>> 
>> I have not studied it.  I always try to avoid having more than an
>> order of magnitude more inodes than I need, it also saves fsck time.
>> 
>
>So what's the appropriate way to calculate what blocksize and how many 
>inodes you should use?

"Know your data" :-/

"df -i" will report both block and inode usage for a filesystem.

You adjust number if inodes by specifying the expected average
number of bytes per inode (== bytes_used / inodes_used) to newfs.

block/fragment I have not heuristics for, but I think 32/4 is
a good alround setting for multi-GB disks.


-- 
Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
phk@FreeBSD.ORG         | TCP/IP since RFC 956
FreeBSD committer       | BSD since 4.3-tahoe    
Never attribute to malice what can adequately be explained by incompetence.