Re: A problem about DIRECT IO on ext3

[Jens Axboe]

On Mon, Aug 29 2005, Erik Mouw wrote:
> There are four prerequisites for direct IO:
> - the file needs to be opened with O_DIRECT
> - the buffer needs to be page aligned (hint: use getpagesize() instead
>   of assuming that a page is 4k
> - reads and writes need to happen *in* multiples of the soft block size
> - reads and writes need to happen *at* multiples of the soft block size

Actually, the buffer only needs to be hard block size aligned, same goes
for the chunk size used for reads/writes.

-- 
Jens Axboe

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