The right data (compressible) with the right R/W mix can be very beneficial. We compress SMF data on disk and SVC dumps using SMS. Both compress well and the performance in many use cases has been improved as well as considerable disk space savings. Innovation IAM compression is great and very CPU efficient combined intelligent buffering makes for significant I/O reduction. IMS databases compressed with DBT and DB2 compressed using native DB2 facilities both save us terabytes of disk space without impacting performance. It takes CPU to move lots of empty space around too and disk space here is at least 2X because of Flashcopy backups. I think you will find that selective use of compression can be very beneficial and would suggest don't rule it out because of "benchmark" results.
Best Regards, Sam Knutson, GEICO System z Team Leader mailto:[email protected] (office) 301.986.3574 (cell) 301.996.1318 "Think big, act bold, start simple, grow fast..." -----Original Message----- From: IBM Mainframe Discussion List [mailto:[email protected]] On Behalf Of Massimo Biancucci Sent: Thursday, November 29, 2012 3:57 AM To: [email protected] Subject: Compression Services again. Hi everybody, I'm interested in deeper informations about compression services provided by SMS. In particular I'd like to know where find documentation on "how does it work". From my observations, compression saves disk space but it's not a "good idea" from a CPU (and it's obvious) and elapsed time (less obvious) point of view. For instance, in a simple read-compress/write-compress program (few logic), CPU consumption is really high (60% more) and Elapsed too (25% more) if compared to read-compress/write-on-tape. The normal answer could be "it depends", anyway your response will be really appreciated. Do you use compression ? What's the rule of thumb do you use ? Finally, it seems there's no zAAP/zIIP use (zOS 1.11) for such a service. Thanks in advance. Massimo ==================== 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: INFO IBM-MAIN
