UNIX semantics do permit full support for asynchronous I/O

[Barry Shein]

From: steve at nuchat.UUCP (Steve Nuchia) [responding to my note]
>>Do there exist any benchmark or other test results which indicate that
>>adding asynch i/o to unix actually yields a performance improvement?
>
>There is little question that it can dramatically speed up selected
>applications.

I guess that's a way of saying "no, I don't know of any results..."

>Applications, mostly in the backup arena (afio, ddd)
>get substancially improved throughput even using really stupid mechanisms.

Backups almost always use raw I/O, how does this affect this
observation?

Is it worth doing for filesystem (disk) I/O?

Why are these mechanisms "stupid"? Are you sure the same speed-up
would be seen with async I/O? Are there any other applications besides
intensive disk to tape which would benefit from this, or might this be
a singular example?
-- 
        -Barry Shein

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