Disk I/O Tuning is absolutely possible and in fact is the single biggest opportunity we have in most cases.
DFSMSdfp options offer a great many choices to increase the performance with system managed buffering, compression, stripes, and more. Compression is a space utilization and performance enhancement with data like SMF records, SVC dumps, and other data with easily compressed content. I use compressed and striped on all the intermediate files dumped from the SMF MANX datasets and it works great reduced processing time to about 1/4 of what it was. Chuck Hopf has this and some other great tips in his MXG presentation. If you use MXG or don't it's still some great information on how to handle processing lots of SMF data. Visit http://www.mxg.com/downloads.asp and scroll down to "MXG Simplified (2004) Chuck Hopf" to download a copy. It sounds like you are still on ESCON channels. If you can spend some money rather than buying more ESCON channels start trying to figure out how you can migrate to FICON channels. The best I/O is of course no I/O so look at the opportunities to eliminate stupid I/O with bad block sizes you can fix, repetitive PDS I/O you can eliminate by using PDSE or LLA when you cannot change the program, etc. Best Regards, Sam Knutson, GEICO Performance and Availability Management mailto:[EMAIL PROTECTED] (office) 301.986.3574 "Think big, act bold, start simple, grow fast..." -----Original Message----- I'd say if you can go to 8 channels in width, without incurring an unacceptable cost, go for it. It's better redundancy, resiliency, and the need for more data faster only increases over time so extra width is generally a good thing. Regards, Gary Diehl -----Original Message----- From: IBM Mainframe Discussion List [mailto:[EMAIL PROTECTED] Behalf Of Ted MacNEIL Sent: Sunday, June 12, 2005 7:00 PM To: [email protected] Subject: Re: Disk I/O tuning still possible? ... So, I ask, is I/O tuning still possible, or even necessary? ... <> ==================== This email/fax message is for the sole use of the intended recipient(s) and may contain confidential and privileged information. Any unauthorized review, use, disclosure or distribution of this email/fax is prohibited. If you are not the intended recipient, please destroy all paper and electronic copies of the original message. ---------------------------------------------------------------------- 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
