From: Shawn T. Rutledge <rutledge_at_cx47646-a.phnx1.az.home.com>
Date: Tue Apr 18 13:22:51 2000

On Tue, Apr 18, 2000 at 10:36:20AM -0700, Chuck McManis wrote:
> Track 'n' on all platters formed one cylinder. Given that disks had a hard
> time seeking quickly, things that you could put on one cylinder could be
> accessed like a drum without any head movement. In BSD they added "cylinder
> groups" which were collections of cylinders (usually 3, sometimes 5) where
> the heads need only move in our out one or two steps from the "home"
> cylinder to get to a particular bit of data. Then by clustering data into
> cylinder groups you could acheive higher disk throughput then if you put
> things onto any old track.

Somebody once told me that the definition of a "real pro" database admin
is somebody who can put the right tables on the right cylinders to
optimize throughput. But I didn't know it was an OS-level feature...
guess it would have to be.

  _______                   Shawn T. Rutledge / KB7PWD  ecloud_at_bigfoot.com
 (_  | |_)          http://www.bigfoot.com/~ecloud  kb7pwd_at_kb7pwd.ampr.org
 __) | | \________________________________________________________________
Get money for spare CPU cycles at http://www.ProcessTree.com/?sponsor=5903
Received on Tue Apr 18 2000 - 13:22:51 BST

This archive was generated by hypermail 2.3.0 : Fri Oct 10 2014 - 23:32:41 BST