Re: choosing the file system block size

[Edgar Fuß <ef%math.uni-bonn.de@localhost>]

> Whether these means you can ignore them depends
> on exactly what you care about; you know that better than I.
What I'm trying to do is to figure out the optimal block/fragment size for
a filesystem. My idea is to take the given data set and, for various
block/fragment sizes, compute the overhead caused by that choice. So I can
find out not only what the optimal values are, but also how much it
actually matters.

What I have so far is a Perl script that computes, given block/frag size,
the number of fragments, data blocks and indirect blocks from a find -ls
output.

Since I'm not interested in the real amount of space required, I can ignore
super blocks, cylinder group heads and inodes, since the space required by
them doesn't vary with the choice of block size.

Now, what else do I need? I need one bit per fragment for the free list,
plus one bit per block for the cluster map. But what do I need for the
summary infomation? What else have I forgotten?


I can, of course, post the Perl script if somebody is interested in it.