jones@eglin.af.mil (Calvin Jones, III) (01/16/90)
Dave Lowrey <dwl10@uts.amdahl.com> asks: > Here is my question....which cylinder is "best"? The default, as > suggested by the PREP program, was the last cylinder. At first, this > seemed logical, as most of the data I would be accessing will be in > the "upper half" of the cylinders. > > However, someone has told me that most of the lubricant for the heads > lie inside of track 0 (wouldn't centrifigal force cause the lubricant > to spread toward the outside oof the platters?). > > Does anyone have any idea on the "best" place to park my heads? First, cylinders on your drive are numbered from the outside to the inside, with 0 being the outermost cylinder. The *BEST* place to park the head assembly is actually to have it move INSIDE the last data track on the disk. This is where the drives that autopark on power off move it. Since you can't get the heads beyond the highest numbered cylinder, that one is the best place. The reason for this is that IF the drive is jarred and the heads happen to contact the surface, the surface is moving much slower at the center of the disk than at the edge. If you want to be even safer, set the park zone to the highest cylinder, then partition the drive so that the last dozen, or so, cylinders are a separate partition and make sure that the data in that partition is never critical. (Or better, just don't use those cylinders --- consider them as your sacrifice to the Great god of rotating mass storage.) --- Cal // Cal Jones - Internet: <Jones@UV4.Eglin.AF.Mil> \X/ BBS: 904-243-6219 1200-9600HST 340Meg, all Amiga Single Tasking? *JUST SAY NO!!!*