Re: ADRDSSU Compatibility
On 11/18/2011 04:15 PM, Ted MacNEIL wrote: I'm glad to know "n-2" compatibility is now supported. If that were true long ago when the previous dfdss 64KiB change was made, it certainly wasn't advertised then. Funny, I thought n-1 was supported for a long time! - Ted MacNEIL eamacn...@yahoo.ca Twitter: @TedMacNEIL Obviously this depends on what is meant by "compatibility" PTFs. New dfdss versions have always been compatible in reading dumps produced by previous version(s) - changes that invalidated archived dfdss tapes would not be tolerable.. I also can't recall a case other than the 64K block size change where the n-1 version wasn't able to read tapes produced by version n as long as you didn't explicitly use some new features introduced in the new version. The problem with the 64K block change was that you got the new feature by default. I may have missed it, but I don't remember there being a PTF to the old version to allow it to read 64K blocks, at least not at the time we migrated. In some cases the best you can hope for is toleration support for the n-1 version so that it will try to do something reasonable or at least give meaningful warnings or errors if there is some new construct in the dump file related to a new feature in version n that the old version can't fully handle. -- Joel C. Ewing,Bentonville, AR jcew...@acm.org -- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@bama.ua.edu with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
Re: ADRDSSU Compatibility
>I'm glad to know "n-2" compatibility is now supported. If that were true long >ago when the previous dfdss 64KiB change was made, it certainly wasn't advertised then. Funny, I thought n-1 was supported for a long time! - Ted MacNEIL eamacn...@yahoo.ca Twitter: @TedMacNEIL -- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@bama.ua.edu with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
Re: ADRDSSU Compatibility
On 11/18/2011 08:18 AM, Norbert Friemel wrote: On Fri, 18 Nov 2011 07:42:34 -0600, Joel C. Ewing wrote: ... But, take note that this backward compatibility does not always exist. It seems that about every ten years or so as tape technology advances IBM decides to raise the block size written by dfdss, first to 64KiB, relatively recently to 256KiB. Be sure to pay attention when this is mentioned in migration notes, because it invariably means that new dump tapes CANNOT be read by back-level versions of dfdss, and you might not have complete control over or knowledge of the update level of dfdss at a recovery site. IBM supports "n-2" releases. The 256K blocks were new in z/OS 1.12. There are compatibility PTFs for 1.10 and 1.11 (OA30822). Norbert Friemel I'm glad to know "n-2" compatibility is now supported. If that were true long ago when the previous dfdss 64KiB change was made, it certainly wasn't advertised then. The fact that compatibility PTFs for back-level releases are available still doesn't mean you can assume without checking that they are actually installed at some DR site not under your direct control, or that you don't need to be extra careful at such junctures that you have updated all your stand-alone dfdss tapes and have resolved compatibility issues on any back-level systems on site that could conceivably become an issue for local recovery. It's easy to get complacent about issues that are so rare they at most exist for a few months every decade. -- Joel C. Ewing,Bentonville, AR jcew...@acm.org -- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@bama.ua.edu with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
Re: ADRDSSU Compatibility
On Fri, 18 Nov 2011 07:42:34 -0600, Joel C. Ewing wrote: >... >But, take note that this backward compatibility does not always exist. >It seems that about every ten years or so as tape technology advances >IBM decides to raise the block size written by dfdss, first to 64KiB, >relatively recently to 256KiB. Be sure to pay attention when this is >mentioned in migration notes, because it invariably means that new dump >tapes CANNOT be read by back-level versions of dfdss, and you might not >have complete control over or knowledge of the update level of dfdss at >a recovery site. > IBM supports "n-2" releases. The 256K blocks were new in z/OS 1.12. There are compatibility PTFs for 1.10 and 1.11 (OA30822). Norbert Friemel -- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@bama.ua.edu with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
Re: ADRDSSU Compatibility
On 11/18/2011 07:11 AM, Norbert Friemel wrote: On Fri, 18 Nov 2011 10:26:32 -0200, Carlos Bodra - Pessoal wrote: If I have a volume backed up using ADRDSSU 1.11 (DUMP DATASET) is possible to restore it using ADRDSSU 1.10? (backward compatibility) -- Yes, if the coexistence and fallback PTFs are installed on z/OS 1.10 http://publibz.boulder.ibm.com/cgi-bin/bookmgr_OS390/BOOKS/E0Z2M171/2.1.2.1 Norbert Friemel ... But, take note that this backward compatibility does not always exist. It seems that about every ten years or so as tape technology advances IBM decides to raise the block size written by dfdss, first to 64KiB, relatively recently to 256KiB. Be sure to pay attention when this is mentioned in migration notes, because it invariably means that new dump tapes CANNOT be read by back-level versions of dfdss, and you might not have complete control over or knowledge of the update level of dfdss at a recovery site. Although we never had to work around a dfdss failure, our DR tape set always included our current version of stand-alone dfdss, just in case - so we knew we could always restore our emergency restore system (at same software level as production) and didn't have to constantly remember to verify DR site dfdss compatibility that only rarely would be an issue. -- Joel C. Ewing,Bentonville, AR jcew...@acm.org -- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@bama.ua.edu with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
Re: ADRDSSU Compatibility
On Fri, 18 Nov 2011 10:26:32 -0200, Carlos Bodra - Pessoal wrote: >If I have a volume backed up using ADRDSSU 1.11 (DUMP DATASET) is >possible to restore it using ADRDSSU 1.10? (backward compatibility) >-- Yes, if the coexistence and fallback PTFs are installed on z/OS 1.10 http://publibz.boulder.ibm.com/cgi-bin/bookmgr_OS390/BOOKS/E0Z2M171/2.1.2.1 Norbert Friemel -- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@bama.ua.edu with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
ADRDSSU Compatibility
If I have a volume backed up using ADRDSSU 1.11 (DUMP DATASET) is possible to restore it using ADRDSSU 1.10? (backward compatibility) -- Carlos Bodra São Paulo - SP Brazil -- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@bama.ua.edu with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
