Date: Tue, 11 Mar 1997 11:09:15 -0600 From: Chris Csanady <ccsanady@nyx.pr.mcs.net> To: Tom Samplonius <tom@sdf.com> Cc: Michael Hancock <michaelh@cet.co.jp>, Brian Tao <taob@vex.net>, "matthew c. mead" <mmead@goof.com>, isp@freebsd.org, hackers@freebsd.org Subject: Re: freebsd as a news server? Message-ID: <199703111709.LAA04536@nyx.pr.mcs.net> In-Reply-To: Your message of Mon, 10 Mar 1997 19:46:37 -0800. <Pine.NEB.3.94.970310194240.27200A-100000@misery.sdf.com>
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> >On Tue, 11 Mar 1997, Michael Hancock wrote: > >> On Mon, 10 Mar 1997, Tom Samplonius wrote: >> >> > On Tue, 11 Mar 1997, Michael Hancock wrote: >> > >> > ... >> > > I've been using -i 3072 -b 4096 -f 1024 -a 8 for non-binary newsgroups a nd >> > > the default for binary newsgroups. >> > > >> > > This way news articles on average will fit in a block. >> > >> > You always want maxcontig to beigger than 8. It has nothing to do with >> > file allocation, only have many sectors are transfered at once to the >> > driver. >> >> And the magic number is ____. > > As big as possible. All the disk drivers should be able to handle at >least 128. I don't really know how big it can be. 256? 1024? > > A too small maxcontig will hamper scatter/gather. I noticed that by >looking at the sps and tps values from iostat that it was never >transfering more than 16 sectors per transfer. I bumped up maxcontig, and >noticed a nice performance increase (at least for my application). I thought that there is currently a 64K io limit imposed due to some bogosity. Any know if this ever got fixed? If this is so, I assume 8 is the maximum if you use 8K blocks. Or 128, if they are talking about sectors in tunefs(8).. I don't, but would like to know. :) Chris > > The default maxcontig setting for 2.1.x is just way too small. > >Tom >
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