Ed, Please add your support to this idea, https://ibm-sys-storage.ideas.ibm.com/ideas/DS80-I-198
You may wish to look at Frank Kyne's recent article in the Watson & Walker newsletter. Lennie Dymoke-Bradshaw https://rsclweb.com ‘Dance like no one is watching. Encrypt like everyone is.’ -----Original Message----- From: IBM Mainframe Discussion List <[email protected]> On Behalf Of Ed Jaffe Sent: 06 August 2023 19:54 To: [email protected] Subject: Permanent Incremental FlashCopy Relationships? (Was: SETROPTS ERASE...) On 7/28/2023 5:04 AM, Larre Shiller wrote: > That said, you might want to check out IBM APAR OA61492 (and associated PE > fixes). The DASD UNMAP function (or the non-IBM DASD equivalent) seems to > perform "the same" Erase-On-Scratch function... but at the hardware level. > We are using the EMC equivalent and it is working seamlessly--no z/OS side > overhead at all and practically nothing at the DASD hardware level. Dude! I can't believe I didn't know about this awesome new feature!! Thanks for posting... The only troubling part is this restriction: * This support is available when all of * * these conditions are met: * * - data sets are on volumes not in copy * <---!!! * services relationships * <---!!! Our primary DASD volumes are in permanent incremental FlashCopy relationships in order to reduce pressure on the DASD subsystem when full-volume FlashCopy is needed for dumps, etc. I got the impression after listening to a presentation from Glenn Wilcock at SHARE that this was a best practice. Perhaps I misunderstood him or things have changes since then, but either-way I'm starting to rethink that practice. Another similarly-restricted function is the DSS SPACEREL command, which we issue periodically on our SMS storage groups. Like this UNMAP feature, it won't work with active copy services relationships. In that case, we withdraw those relationships prior to running the SPACEREL function. But that's something we do only a couple/few times a year so it's not a big deal. It sounds like EMC DASD doesn't have these restrictions? I'm betting Hitachi doesn't either, but I don't know for sure... I wonder what other IBM DASD clients are doing? -- Phoenix Software International Edward E. Jaffe 831 Parkview Drive North El Segundo, CA 90245 https://www.phoenixsoftware.com/ -------------------------------------------------------------------------------- This e-mail message, including any attachments, appended messages and the information contained therein, is for the sole use of the intended recipient(s). If you are not an intended recipient or have otherwise received this email message in error, any use, dissemination, distribution, review, storage or copying of this e-mail message and the information contained therein is strictly prohibited. If you are not an intended recipient, please contact the sender by reply e-mail and destroy all copies of this email message and do not otherwise utilize or retain this email message or any or all of the information contained therein. Although this email message and any attachments or appended messages are believed to be free of any virus or other defect that might affect any computer system into which it is received and opened, it is the responsibility of the recipient to ensure that it is virus free and no responsibility is accepted by the sender for any loss or damage arising in any way from its opening or use. ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
