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Re: PWRDWNSYS



fixed

http://www-01.ibm.com/support/docview.wss?uid=nas161209687dac0128386256d630055b0b0doesn't
mention controller cache one way or the other WRT controlled v.
immediate. But given the descriptions say the system does the exact same
thing once jobs have been ended I find it a little hard to believe there's
a difference in the way disk controllers are handled.

This PTF (for 6.1) gives you command-line access to battery cache info:
http://www-912.ibm.com/a_dir/as4ptf.nsf/d274b8e7d37f34a786256e320076c355/52a41eed761ffbc38625775a006e4ee1?OpenDocument


On Wed, Jan 16, 2013 at 2:11 PM, Gqcy <gmufasa01@xxxxxxxxx> wrote:

currently, the batteries on my system have day counters.
count the number of days up.
count the ADJUSTED number of days up (I see it has a heat check).
count down the number of days to warning.
count down the number of days to error.

Does the system also have checks to see how the batteries ACTUALLY
are performing?

...
Wouldn't it be documented somewhere that the
PWRDWNSYS *CNTRLD performs differently
from PWRDWNSYS *IMMED from a disk cache perspective?









On 1/16/2013 1:22 PM, Evan Harris wrote:
My understanding is that the batteries are there to cater for
precisely this situation.

They (the cache batteries) aren't powered externally; they ensure the
cache guaranteed power and is therefore protected in the case of an
unexpected power loss.

That's why when the cache batteries fail, your performance is degraded
- the system doesn't use the cache as it is no longer guaranteed
protected.

On Thu, Jan 17, 2013 at 7:52 AM, Jeff Crosby<jlcrosby@xxxxxxxxxxxxxxxx>
wrote:


Would the cache batteries have held properly from whenever the UPS
batteries went dead until 1pm?

When unstable utility power was restored at 1pm (9 hours), then some
power
would have been coming from the UPS. Since nothing else on the UPS was
powered on, I assume whatever little power was available from the UPS
would
have been enough to power the control panel/service processor/green
light
on the front of the system and therefore would be supplying power to the
cache batteries.

Does what I just wrote make sense?






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