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Re: Performance problem creating large files

In article
<email@hidden>, Steven
Bytnar <email@hidden> wrote:

> Through the examples above, I've demonstrated that running this test
> program against a HFS+ volume under MacOS 9.2.2 natively results in
> very quick execution. About 1 second. And, under MacOS X, any attempt
> to create a large file using BSD or Classic or Carbon results in
> a significant (and I might add unacceptable) delay.

That's because Mac OS 9 and earlier just allocate the space but don't
fill it with zeroes. That means you can read from the file and get
whatever data happened to be on that spot on the disk before you grew
your file. Every once in a while, this causes big panics as people
think some program has been secretly collecting all their most
important data, when the program really just created a scratch file and
never actually used the space.

Since Mac OS X (and UNIX upon which it is based) is more security
conscious, it zeroes out that data so other programs cannot
accidentally or purposefully snoop your data.

-Mark
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References: 
 >Performance problem creating large files (From: Steven Bytnar <email@hidden>)
 >Re: Performance problem creating large files (From: Umesh Vaishamapayan <email@hidden>)



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