Hi Tom and thank you a lot for your reply. WLC is a thing I cannot influence as it's managers' decision. But not using storage you bought and could be very useful seems to me a waste of money without a valid reason. Using it could increase performance and save some CPU to be used for customers. Sometime our capping is so looooong that all jobs are delayed a lot, expecially batch.
Thank you again and best regards Max Scarpa "Kelman, Tom" <[EMAIL PROTECTED]> Sent by: IBM Mainframe Discussion List <IBM-MAIN@BAMA.UA.EDU> 07/11/2007 14.51 Please respond to IBM Mainframe Discussion List <IBM-MAIN@BAMA.UA.EDU> To IBM-MAIN@BAMA.UA.EDU cc Subject Re: Real storage usage - a quick question Here is how I see the answers to the naysayers. 1. The CPU overhead incurred because of the addition of memory blocks would be minimal and you'd probably actually buy back CPU overhead because of things such as less I/O. Adding more memory blocks would allow you to retain more data in memory (DB2 buffers for example) and reduce I/O. In my mind I/O overhead would be a lot more CPU intensive than any memory overhead. 2. Yes, increasing the memory would probably cause the workload to increase slightly. There is always a tit-for-tat situation where you fix one bottleneck in a system another will pop up. However, it sounds like your limiting your CPU usage based on software costs. While I understand the budget thing you also have to decide if you're hurting your customers by doing that. Is your DB2 processing so slow because of the lack of memory that your customers are complaining? 3. So you're paying for 5GB of storage that you aren't using. Is that really a good use of budget resources? > Sent: Wednesday, November 07, 2007 4:00 AM by Max Scarpa > > Esteemed listers > > I've a problem but I haven't any answer to it or better I've different > answers. > > Say we have a machine with, just to say, 10 Gb of real storage. Only 5 are > used by the only LPAR defined (actually there's another very small LPAR, > but it's real small), which is a WLC LPAR and often it's CPU capped. 5 Gb > remain unused. I asked why, as I'd like to enlarge my bufferpools in DB2 > (for instance). I've got these answers: > > - Increasing real storage increases cpu overhead to managed more memory > blocks in a cpu-constrained machine. > - Increasing real storage causes more workload so more chanches to hit WLC > capping. > - It's better to have some spare storage (5 Gb ?). > > Our workload is increasing and we have some occasional paging spikes. DB2 > doesn't perform well due to too small pools. > > According listers' experience, is using the most part/all real storage > (perhaps with a spare memory for future incrases) a real problem ? Did > anyone experimented any problem ? What are guidelines ? > > Thank you in advance > > Max Scarpa > ***************************************************************************** If you wish to communicate securely with Commerce Bank and its affiliates, you must log into your account under Online Services at http://www.commercebank.com or use the Commerce Bank Secure Email Message Center at https://securemail.commercebank.com NOTICE: This electronic mail message and any attached files are confidential. The information is exclusively for the use of the individual or entity intended as the recipient. If you are not the intended recipient, any use, copying, printing, reviewing, retention, disclosure, distribution or forwarding of the message or any attached file is not authorized and is strictly prohibited. If you have received this electronic mail message in error, please advise the sender by reply electronic mail immediately and permanently delete the original transmission, any attachments and any copies of this message from your computer system. ***************************************************************************** ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
