Re: DASD arm worksheets

Hi,

You may want to use IBM's Workload Estimator (WLE), it can give you a
good idea while configuring disks. You can check IBM's performance site:

http://www-03.ibm.com/servers/eserver/iseries/perfmgmt/resource.html


There is a PDF about WLE and disk config here:

http://www-03.ibm.com/servers/eserver/iseries/perfmgmt/pdf/wledisk.pdf


Regards,

Luis Rodriguez


> -----Original Message----- From: "ChadB@xxxxxxxxxxxxxxxxxxxx" <ChadB@wheeling-
> nisshin.com> To: "Midrange Systems Technical Discussion" <midrange-
> l@xxxxxxxxxxxx> Sent: 5/2/06 10:13 AM Subject: DASD arm worksheets
>
>
> Does anyone know if IBM still publishes the "DASD Arms Required for
> Performance" type worksheets for the i5 models?  I've used them in the
> past as an additional measure of insurance when designing a new
> system, but the last time I used one was for an 800.  We're starting
> to spec out a new 520 to replace the 800 and with the Domino and
> Websphere workloads I KNOW we've had disk arm/controller issues in the
> past, so I want to ensure a good config.  The 800 was originally
> spec'ed by the previous admin/BP with a 5702 controlling 6 mirrored
> drives and the box performed horribly.  I got it switched over to a
> RAIDed 2757 and made a positive impact (and want that to carry over to
> the new box!).
>
> In addition to the DASD arms worksheet, i'm looking for some input on
> the 757mb cache and 40mb cache RAID controllers available for the i5s.
> We're hoping to keep this box to just a system enclosure and I think
> with the 520s all the 757mb controllers are not permitted in the
> system enclosure. Is this true?  If so, i'm wondering how a 40mb
> controller will fare in comparison to the current 2757 (757mb cache)
> we're running.  I would hate to take a step backwards on the disk
> cache... Domino seems to love the increased disk cache.
> --
----------------------------
Luis Rodriguez
IBM Certified Systems Expert
eServer i5 iSeries Technical Solutions
Caracas, Venezuela