Subject: Re: appropriate CCD interleave for LFS
To: Blair Sadewitz <blair.sadewitz@gmail.com>
From: Jason Thorpe <thorpej@shagadelic.org>
List: tech-perform
Date: 11/08/2006 10:07:31
On Nov 7, 2006, at 8:04 PM, Blair Sadewitz wrote:

> Would using a ccd equal to LFS' big block size result in near-optimal
> or optimal performance for, let's say, compiling large amounts of
> source and/or general desktop use?

For LFS, the ideal interleave (for either ccd or RAIDframe) would  
cause an LFS segment to map 1-1 to a row (i.e. to be written to all  
component disks in parallel).  This is ideal because LFS writes out  
entire segments at a time.  So, basically, "(segment_size_in_bytes /  
number_of_disks) / 512" to get the ccd interleave factor (which is  
expressed in blocks, IIRC).

-- thorpej