Coda File System

simple readahead ?

From: Enrico Weigelt <>
Date: Fri, 20 Apr 2007 14:24:15 +0200
Hi folks,

Coda still suffers from being extremly slow on long distance links
(ie. DSL) when files are not yet cached. The prrimary problem: 

Applications tend to read sequently. So the normal process is, the
app reads some bit, then venus asks the next block from the server,
if the server's reply received the app gets its data, then it 
reads the next data and so on.

So the whole process is strictly sequential and suffers from the
network latency. An easy solution could be an simple readahead:
Venus fetches more data from the server than actually requested
by the app. An simple policy could be, always try to have one 
or two blocks more in the cache after the open file pointers.

 Enrico Weigelt    ==   metux IT service -
 Please visit the OpenSource QM Taskforce:
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Received on 2007-04-20 08:29:35