Re: Leaving IBM i on vs. sleep mode and fire it up now and then

[Vernon Hamberg <vhamberg@xxxxxxxxxxxxxxx>]

I had thought the stiction (STatic frICTION, the friction to overcome to 
move things from a standstill), came from humidity forming a "bubble" 
(?) between the head and the surface - surface tension could have been 
the culprit.

That seems now to be not enough to keep it from moving, but there is a 
link to an explanation that makes sense and does mention the fix of 
striking the drive against something - or quickly rotating it in your 
hand. And what has been done - seems this is almost a non-issue now - 
the heads get parked away from the surface now.

https://forum.hddguru.com/viewtopic.php?f=1&t=26090

Vern

On 1/16/2017 6:34 AM, Rob Berendt wrote:
> I also question whether that was "sleep" mode or was just as operationally
> disruptive as yanking the power cord.  I am curious as to what QIPLSTS was
> upon waking up from such an outage.  I think I would tend to stick to
> PWRDWNSYS *CNTRLD DELAY(120)
> After shutting down the rest of your options, doing the ENDTCP and the
> ENDSBS.
> Now on 7.2 and above there's a few more things I would do also.
>
> Now, back to the question...
> Back in the day there was this thing called "stiction".  This was where a
> system would not power up without a disk error.  One would have to remove
> the disk drives, give them a few light taps, stick them back in and try
> them again.  Not really sure how long of a power outage is necessary
> before the grease congeals or whatever it was that caused this.
>
> If you have the machine under maintenance and can do without it for a day
> or so waiting for IBM to fly in the parts for that old machine from the
> opposite side of the country then that's not really a problem.  Hey
> occasional full shutdowns followed by an IPL are going to be when hardware
> is given more of the full diagnostics.
>
>
>
> Rob Berendt