On the way to a multitrack HD recording suite for Linux, there comes the moment when you will meet the disk throughput frontier. This page covers some information on maximizing data rates and reducing seek times.
Here is a thread about disk fragmentation, pre-allocation and other things of importance for HD recording applications (from the Archive). Includes insightful posts from linux-fsdevel folk, notably Stephen C. Tweedie.
Another thread about disk I/O griefs.
Some good news for IDE disk users can be found here.
A mmap() discussion from LKML with a comment from Linus can be found here at the Kernel Traffic Site.
Frank Neumann gave this pointer to an article in ProRec magazine about SCSI vs. IDE. It spawned a thread that might be of interest.
Again, if you have found other threads on LAD or elsewhere to be particularly useful with respect to disk issues or have further sources of enlightenment, please share them.