Re: Converting MIM to GRS
I seem to started a robust discussion --- thanks everyone. We have been a MIM shop for many years and it has been rock solid. The quesion with my shop is this: We are a single 7 image Sysplex - no outside systems sharing resources and we use sysplex tape sharing provided by z/OS. Outside the job requeue feature, what additional benefit justifies the cost in my scenario? -- 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
Re: Converting MIM to GRS
I'd like to add a few other thoughts onto of Mark's comments. Yes, I do work for CA, and have supported MIM. Just a disclosure, lest some people accuse me of hiding my true identity. I'm sure there are some with some negative impressions of MIM; but I did want to mention what our very large customers have been doing (Mark's site would be considered large). MIM can use Control Files on Shared (FICON) DASD, XCF, XES, or CTCs (SCTCs or FCTCs). All provide excellent performance (when properly tuned). MII (Multi-Image Manager Integrity) has been used in many shops primarily for Volumes spanning Sysplexes, sometimes spanning Data Centers. MII does learn about how data sets are opened so a long list of Inclusions or Exclusions are not really needed. Recovery of MII or restarting it is very easy to do. No system outages required... MIA (MIM Allocation) has been used in many shops for sharing Tape devices (real/reel devices, ATLs, VTS, VTAPE) across Sysplexes. Again, within the same site or remote. Remote Tape device usage has increased in many shops with D/R considerations. MIA can also manage devices with z/VM and Linux Guests (something that is increasing in need). MIC (MIM Console) has been used in many shops for consolidating z/OS consoles. Again, consolidation is across Sysplexes and sites, and can be used to consolidate z/VM and Linux Guests. This is very useful in Server Consolidations on z/VM. Support for all of the MIM functions has been very good over the years, and support for new hardware and Operating Systems on day 1, has always been there. -Original Message- From: IBM Mainframe Discussion List [mailto:[EMAIL PROTECTED] On Behalf Of Mark Zelden Sent: Wednesday, September 21, 2005 SYSN 3:06 PM To: IBM-MAIN@BAMA.UA.EDU Subject: Re: Converting MIM to GRS On Wed, 21 Sep 2005 00:00:00 GMT, Ted MacNEIL [EMAIL PROTECTED] wrote: MIM in the CF performs just as well as GRS*. But, I'd rather use the 'free' GRS. And, I've had too many problems with a certain ISV. Perhaps, but MII has been very solid code and bery good support over the years. Also more dynamic changes than GRS - especially in past years. I've had some issues with MIA (tape) in the past, but no glearing problems with MII (integrity). No one ever mentions MIC in these threads. While sysplex will let you consolodate your consoles within a sysplex, with MIC you can issue commands and view console messages that span the boundries of sysplex. Most people miss the fact that MIM can run with a control file in the CF and perform as well as GRS STAR, but many shops that run MIM do so specifically because it can span sysplexes. Also, some recent threads (and past threads) talk about a DASD shared control file. While you can do that, the best option is CTCONLY which uses 2 sets of CTCs (primary + backup) for communications and has a virtual control file that lives on one of the active LPARs in the MIMplex. Obviously if you have FCTCs your better off than with ESCON CTCs. It's not GRS STAR (or MIM in a CF), but performance is still good. Mark -- Mark Zelden Sr. Software and Systems Architect - z/OS Team Lead Zurich North America and Farmers Insurance Group mailto: [EMAIL PROTECTED] Systems Programming expert at http://Search390.com/ateExperts/ Mark's MVS Utilities: http://home.flash.net/~mzelden/mvsutil.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
Re: Converting MIM to GRS
Would anyone have any useful information (presentations, hints tips) when considering a migration. ... BOEING had somebody give a presentation 3-4 years ago. Check SHARE. Also: 1. Ring doesn't perform well, but must be used in a multi-plex environment. 2. You cannot cross plex boundaries with GRS*, since you cannot share CF's between plexes. 3. A lot of people miss this. The MIM $H;$E;$C combination is not done by GRS. So, depending on the batch activity queueing, you may need more inits (approx 10% more) if you have a lot of that. The inits are held for both enq delay and execution after resolution. -teD In God we Trust! All others bring data! -- W. Edwards Deming -- 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
Re: Converting MIM to GRS
There's nothing that beats GRS star, but if that is not doable, you're better off staying with MIM. I've heard that advice from IBM account reps! ... MIM in the CF performs just as well as GRS*. But, I'd rather use the 'free' GRS. And, I've had too many problems with a certain ISV. -teD In God we Trust! All others bring data! -- W. Edwards Deming -- 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
Re: Converting MIM to GRS
On Wed, 21 Sep 2005 00:00:00 GMT, Ted MacNEIL [EMAIL PROTECTED] wrote: MIM in the CF performs just as well as GRS*. But, I'd rather use the 'free' GRS. And, I've had too many problems with a certain ISV. Perhaps, but MII has been very solid code and bery good support over the years. Also more dynamic changes than GRS - especially in past years. I've had some issues with MIA (tape) in the past, but no glearing problems with MII (integrity). No one ever mentions MIC in these threads. While sysplex will let you consolodate your consoles within a sysplex, with MIC you can issue commands and view console messages that span the boundries of sysplex. Most people miss the fact that MIM can run with a control file in the CF and perform as well as GRS STAR, but many shops that run MIM do so specifically because it can span sysplexes. Also, some recent threads (and past threads) talk about a DASD shared control file. While you can do that, the best option is CTCONLY which uses 2 sets of CTCs (primary + backup) for communications and has a virtual control file that lives on one of the active LPARs in the MIMplex. Obviously if you have FCTCs your better off than with ESCON CTCs. It's not GRS STAR (or MIM in a CF), but performance is still good. Mark -- Mark Zelden Sr. Software and Systems Architect - z/OS Team Lead Zurich North America and Farmers Insurance Group mailto: [EMAIL PROTECTED] Systems Programming expert at http://Search390.com/ateExperts/ Mark's MVS Utilities: http://home.flash.net/~mzelden/mvsutil.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
Re: Converting MIM to GRS
Mark, I have been advocating this migration in our Sysplex and here are excerpts from an emails I wrote with links that may help. The first IBM implementation of tape sharing back in MVS/ESA 5.2.2 had many faults. The rewrite IBM did a while ago commonly called ATS Star works very well and is included free in base z/OS. A number of other sites have used this base feature to replace GTAF (MIA). $SNIP It is documented in SA22-7625 MVS Setting Up A Sysplex Appendix G.0 Appendix G. Specifying Automatic Tape Switching (ATS STAR) http://tinyurl.com/aswzw Or http://publibz.boulder.ibm.com/cgi-bin/bookmgr_OS390/BOOKS/IEA2F132/CCONTENT S?SHELF=IEA2BK34DN=SA22-7625-06DT=20030423145429 See also GA22-7525 HCD Planning 2.3.3 Using automatic tape switching http://publibz.boulder.ibm.com/cgi-bin/bookmgr_OS390/BOOKS/IEA2G841/CCONTENT S?DT=20040421150502= Or http://tinyurl.com/ceo6x Finally a really excellent set of SHARE presentation by the designer Scott Fagen (IBM) and a couple users. SNIP from the SHARE web site here http://ew.share.org/proceedingmod/abstract.cfm?abstract_id=4823 2811 - ATS Star Implementation, Diagnostics, and User Experiences Available with z/OS 1.2 and installation of selected APARs, ATS Star improves the availability and system management characteristics of MVS Automatic Tape switching function. The speakers will discuss: The new design for Sysplex tape sharing Requirements for implementation IEFAUTOS migration Problem diagnosis and recovery User experiences OEM tape sharing migration I hope that helps. Best Regards, Sam Knutson, GEICO Performance and Availability Management mailto:[EMAIL PROTECTED] (office) 301.986.3574 This time, like all time, is a very good one if we but know what to do with it. - Ralph Waldo Emerson -Original Message- From: IBM Mainframe Discussion List [mailto:[EMAIL PROTECTED] On Behalf Of Mark Wilson Sent: Monday, September 19, 2005 5:19 PM To: IBM-MAIN@BAMA.UA.EDU Subject: Converting MIM to GRS Hi, I have been given a project to migrate one of our customers systems from MIM to GRS. I have a good understanding of both MIM and GRS both have never actually done a migration before. Would anyone have any useful information (presentations, hints tips) when considering a migration. Kind Regards Mark 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
Re: Converting MIM to GRS
I've run each product at different times but never did a conversion. But to me there's one overriding consideration: is all shared DASD within a parallel sysplex? In other words, are you converting to GRS star? If so, go for it. If not, beg your boss not to make you do it. MIM has some big advantages over GRS ring mode, which is far harder to manage, including less dynamic and more prone to serious and far-reaching disruptions. There's nothing that beats GRS star, but if that is not doable, you're better off staying with MIM. I've heard that advice from IBM account reps! . . . JO.Skip Robinson Southern California Edison Company SHARE MVS Program Co-Manager 626-302-7535 Office 323-715-0595 Mobile [EMAIL PROTECTED] IBM Mainframe Discussion List IBM-MAIN@BAMA.UA.EDU wrote on 09/19/2005 02:19:07 PM: Hi, I have been given a project to migrate one of our customers systems from MIM to GRS. I have a good understanding of both MIM and GRS both have never actually done a migration before. Would anyone have any useful information (presentations, hints tips) when considering a migration. -- 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
