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From: =?iso-8859-1?q?Claus=20Guttesen?= <cguttesen@yahoo.dk>
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Subject: Re: Some additional tests run on my performance testing
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Hi.

> Note that doing sequential reads and writes is VERY
> different from doing random reads and writes.  In
the 
> former case, a larger filesystem block size may
reduce 
> fragmentation and help you, but in the latter 
> case---specifically for writes---you're doing twice
> the I/O due to the larger filesystem blocks. Your 
> import and Bill's tests fall into the first
category. 
> It would be interesting to see what sort of
performance 
> you get under a real workload.

Valid point you make there.

My db is up and running now with 16 kb blocks, but I'd
like to try it out with 8 kb blocks.

Can I simply do a file-copy of the database, newfs the
partition with 8 kb blocks, and copy the database back
to take advantage of the 8 kb blocksize?

Or do I have to dump, newfs, create and import the
database?

regards
Claus


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