Re: Are these 8 gigabyte drives causing a problem?

If you have sufficient memory, make sure the "Intelligent Cache" is 
activated.
(Paging Option *CALC for storage pools - F11 from WRKSYSSTS or from 
WRKSHRPOOL).

Neil Palmer      DPS Data Processing Services Canada Ltd.
50 Acadia Avenue, Ste.102                   AS/400~~~~~
Markham, Ontario, Canada.   ____________          ___  ~ 
Phone:(905) 474-4890 x303   |OOOOOOOOOO| ________  o|__||= 
Cell.:(416) 565-1682 x303   |__________|_|______|_|______) 
Fax:  (905) 474-4898         oo      oo   oo  oo   OOOo=o\ 
mailto:NeilP@DPSlink.com  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 
http://www.DPSlink.com     iSeries 400  The Ultimate Business Server





Larry Bolhuis <lbolhuis@arbsol.com>
Sent by: owner-midrange-l@midrange.com
2001/01/18 07:57
Please respond to MIDRANGE-L

 
        To:     MIDRANGE-L@midrange.com
        cc: 
        Subject:        Re: Are these 8 gigabyte drives causing a problem?


Yes.  These drives are too busy!  Anything over 40% for a 5 minute
interval as you have displayed, and the system (and it's users) 'will
notice'.

As to what to do now, Several options (not all good ones):
 1) Stop running so many jobs. (see I told you they weren't all good)
 2) Add memory. This may not help at all of the disk I/O is pure DB. It
may help a lot if the machine is swapping.
 3) Add Drives.  More is better, never too many.  With the numbers below
you're likely to need up to 4 more drives to get performance where it
should be.  Also you are over the 80% reccomended DASD upgrade line
anyway so another 34G (4 drives) wouldn't hurt that in the least either.
 4) Is it possible the machine is filling the write cache on the
controller? You yourself have expressed in the past that this is a bad
thing. More drives wouldn't likely help that much unless you set them up
mirrored instead of RAID.

 Hope this helps!
 
  - Larry


Charly Jones wrote:
> 
> I have been looking at the performance of this machine for the last
> few hours.  Something is wrong.  I think it might be that the 8
> gigabyte drives have enough storage space, but not enough arms.  Is 64
> percent busy a big number?
> 
> What do I do now?
> 
> Charly Jones CSP
> 
> Geezer in Gig Harbor
> 
>                             Work with Disk
> Status                     KHUMBA
>                                                             01/17/01
> 10:31:57
> Elapsed time:   00:05:01 
> 
>              Size    %     I/O   Request   Read  Write   Read
> Write    %
> Unit  Type    (M)  Used    Rqs  Size (K)    Rqs   Rqs     (K)
> (K)   Busy
>    1  6713   8589  83.5   64.2     11.0    26.8   37.4    4.1
> 15.9    51
>    2  6713   8589  83.5   41.5      5.2     6.6   34.8    4.4
> 5.4    38
>    3  6713   8589  83.5   38.0      5.2     3.8   34.1    4.6
> 5.2    35
>    4  6713   8589  83.5   71.3     11.0    18.9   52.4    4.0
> 13.5    64

-- 
Larry Bolhuis
Arbor Solutions, Inc.
(616) 451-2500
(616) 451-2571 -fax
lbolhuis@arbsol.com


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