ZN wrote:
On 6/21/2003 at 11:35 PM Lau wrote:
Back to my earlier mention of caching... hard drives and their controllers do caching as well. I'm not certain if they do read-ahead caching.
In short, yes.
Ta. I'll add a little proviso. The hardware can't know what the next logical sector(allocation unit) for a file is, hence the need for a file system to avoid fragmentation.
Unix (et alia) actually also does (did?) do software read-ahead. It assumed that when you read from a file, you would be wanting to read more of the same, so it initiated the read of the next sector (or whatever) as soon as it gave you the current one.
--
Lau
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