RE: disk cache batteries

["Urbanek, Marty" <Marty_Urbanek@xxxxxxxxxxxx>]

Jim,

Our 820 slowed down big time when the cache batteries needed replaced. Users 
were calling me complaining. It was not subtle - the difference was very 
noticeable. Once we got the batteries replaced, it returned to normal. CE told 
us the batteries usually die at about the same time, and sure enough, we had to 
replace batteries on 3 more LPARs of the same box within about a month of the 
first one.

The reason it impacts the performance so much is because when the cache 
batteries get shaky, the system stops using the cache entirely to ensure data 
integrity in case of a power loss.

-Marty

------------------------------

date: Sun, 17 Apr 2005 18:29:52 -0400
from: "Jim Franz" <franz400@xxxxxxxxxxxx>
subject: disk cache batteries

We finally got thru our fix of disk cache batteries (iSeries 810 only perhaps 4 
years old).
The only clue we had was that the system became extremely slow during a 
conversion test, running about 3 times slower. The CE claimed it shouldn't have 
hit us that hard. I think otherwise - we were running large cpylib, many 
chgpf's of big files, and adding 7 gig of files w/RPG to existing 10 gig.
Manager asking if I can prove it was the batteries (this was our final test 
before go-live). 
Can anyone else confirm losing cache batteries could cause such an effect?

btw- our only clue of hardware problem was wrkdsksts & F11 screen showed disks 
in "degraded" status. After an ipl, we did get following 2 msgs in qsysopr 
queue:
* *Attention*  Contact your hardware service provider now.
Message ID . . . . . . :   CPPEA12       Severity . . . . . . . :   99
A critical system hardware problem has occurred. Critical Message Handler
    has been run.
Message ID . . . . . . :   CPP8988       Severity . . . . . . . :   90

jim franz