Re: Service message: Daylight saving time ends

[Larry Bolhuis <lbolhuis@xxxxxxxxxx>]

Better solution to the Sticktion problem is the one IBM uses. 

   a) Grasp the drive in your hand as if the platters were being held 
by the tips of your fingers.
   b) Rotate the drive rapidly away from you and stop abruptly.  This 
should cause the platters to rotate with the cover and want to continue 
to rotate when you stop the cover. 
   c) Repate b) several times.

   This avoids pounding on the drive and actually gets them 'un-stuck' 
quite often.

   I wouldn reccomend the rapid power cycle option for several 
reasons.  Good power supplies will have a 'crowbar' circuit that won't 
power up if all voltages haven't fallen to zero.  This delays things, 
nullifying the effect.  Not-so-good power supplies don't have this 
circuit and as such the magic smoke could easily be let out of them or 
some other connected componant.  Additionally most SCSI drives power up 
in sequence by their ID so as to limit surges to the power supplies so 
quick power cycling won't reach the stuck drive at all.

   Good Luck!

     - Larry

PaulMmn wrote:

> > Paul [Nelson]... You'll have to define "stiction" ... <smile>
>
>
>
> I'm the "wrong" Paul, but we've had "stiction" over the years...
>
> When a disk has been spinning 24x7x52xN and you power off the machine, 
> very often the disk will not spin back up again.  There are 2 
> potential causes-- (a) lubrication of the bearings is 'gummy' and the 
> motor is not powerful enough to overcome the friction (the disk is 
> 'stuck,' hence STuck+frICTION); (b) in early disks there was actually 
> a dedicated track on the disk where the heads physically touched down 
> on the disk surface when it was powered off.  The heads sometimes 
> would stick to the disk surface, and once again couldn't spin back up.
>
> Solutions to Sticktion:
>
> IF YOU TRY THESE METHODS (other than (a)) I'M NOT RESPONSIBLE IF YOUR 
> SYSTEM IS TOTALLY DEAD FOREVER!!!
>
> (a) never turn off your disk drives
>
> (b) cycle the power several times in quick succession [flip the power 
> on/off/on/off/on rapidly] in the hopes that the pulses of power will 
> overcome inertia and friction (like 'rocking' a vehicle out of a snow 
> bank).
>
> (c) use percussive maintenance on the offending drive (ie give the 
> drive a good >THWACK< on the side with either the heel of your hand or 
> a blunt instrument) in the hope that the impact will jar things loose.

--
Larry Bolhuis                   IBM eServer Certified Systems Expert:
Vice President                    iSeries Technical Solutions V5R2
Arbor Solutions, Inc.             iSeries LPAR Technical Solutions V5R2
1345 Monroe NW Suite 259          iSeries Linux Technical Solutions V5R2
Grand Rapids, MI 49505            iSeries Windows Integration Tecnical 
Solutions V5R2
                               IBM eServer Certified Systems Specialist
(616) 451-2500                    iSeries System Administrator for 
OS/400 V5R2
(616) 451-2571 - Fax              AS/40 RPG IV Developer
(616) 260-4746 - Cell             iSeries System COmmand Operations V5R2