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Re: SPARSE files considered harmful - please revert
>>>>> "Max" == Max Bowsher <maxb@ukf.net> writes:
Max> May I suggest a middle road? Why not let sparse files be configurable as a
Max> $CYGWIN option? This would allow those users who actually want them to
Max> enable them with minimal effort, but keep them off for most users.
I suspect that SPARSE files are genuinely useful, when storing large
files that have holes in them. But I can't imagine one ever wanting
to use SPARSE for all files, because most files aren't like that. So
I don't think sparseness is a good candidate for being put into
$CYGWIN.
We could have a much cleverer implementation of sparseness, if we kept
statistics on the number and size of zero bytes in a file while it was
being written. When we did the close(), we could automatically
transform it into a sparse file. But I don't think even that should
be the default behavior, because it would make all IO slower.
A program I might actually use myself is one that examines a file on
disk to see if it could be stored more compactly as a sparse file, and
transform it if that were the case. Give it a -r option, and you
would have a "disk optimizer". You can do something similar on Unix.
Martin
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