Skip site navigation (1)Skip section navigation (2)
Date:      Fri, 9 Jun 2006 12:53:34 +0200 (CEST)
From:      Oliver Fromme <olli@lurza.secnetix.de>
To:        freebsd-fs@FreeBSD.ORG
Subject:   Re: heavy NFS writes lead to corrup summary in superblock
Message-ID:  <200606091053.k59ArYQs029626@lurza.secnetix.de>
In-Reply-To: <200606081346.04908.mi%2Bmx@aldan.algebra.com>

next in thread | previous in thread | raw e-mail | index | archive | help
Mikhail Teterin <mi+mx@aldan.algebra.com> wrote:
 > The FS is intended for very few very large files and was created 
 > with "newfs -b 65536 -O1" (no softupdates).

Did you also increase the fragment size (-f option)?
The default is 2048 bytes, and I wouldn't expect a b/f
ratio of 32:1 to work very well.  In fact I'm surprised
that you have so little problems.  :-)

If you intend to have very few very large files that are
accessed sequentially most of the time, it is probably
better to set both block and fragment size to the same
value (e.g. 16k), essentially disabling fragmentation.
You should also reduce the inode density by specifying
a larger bytes-per-inode value (-i option), a typical
value would be 262144 (2^18).

Carefully fiddling with the -g and -h options might also
improve performance a bit, see newfs(8).

Best regards
   Oliver

-- 
Oliver Fromme,  secnetix GmbH & Co. KG, Marktplatz 29, 85567 Grafing
Dienstleistungen mit Schwerpunkt FreeBSD: http://www.secnetix.de/bsd
Any opinions expressed in this message may be personal to the author
and may not necessarily reflect the opinions of secnetix in any way.

PI:
int f[9814],b,c=9814,g,i;long a=1e4,d,e,h;
main(){for(;b=c,c-=14;i=printf("%04d",e+d/a),e=d%a)
while(g=--b*2)d=h*b+a*(i?f[b]:a/5),h=d/--g,f[b]=d%g;}



Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?200606091053.k59ArYQs029626>