Wow...sounds like Dual Copy, but for tape. -- All the best, Scott T. Harder
On 5/28/09, O'Brien, David W. (NIH/CIT) [C] <obrie...@mail.nih.gov> wrote: > Thanks Allan, I finally found the section you were quoting and after reading > concede your point. > I've learned something so the day is not a total loss. > > Dave O'Brien > NIH Contractor > ________________________________________ > From: IBM Mainframe Discussion List [ibm-m...@bama.ua.edu] On Behalf Of > Staller, Allan [allan.stal...@kbm1.com] > Sent: Thursday, May 28, 2009 4:38 PM > To: IBM-MAIN@bama.ua.edu > Subject: Re: DFHSM question concerning Duplex copies > > I have not been actively duplexing in a while, but in my past life, > assuming no other problems with the tape, if one or the other tapes of > the primary/duplex pair hit end-of-volume, this would cause a new pair > to start. > > From the z/OS 1.9 DFSMShsm Users Guide SC35-0421-07 Topic 3.4.2.1.1 > > When the original tape reaches its percent-full capacity, DFSMShsm must > flush all the data to both tapes before performing a FEOV. > > If natural EOV is reached on either tape, DFSMShsm marks the tapes as > FULL and restarts processing of the current data set from its beginning > on two new tapes. > > IOW, the shorter tape wins. > > HTH, > > > -----Original Message----- > From: IBM Mainframe Discussion List [mailto:ibm-m...@bama.ua.edu] On > Behalf Of O'Brien, David W. (NIH/CIT) [C] > Sent: Thursday, May 28, 2009 2:21 PM > To: IBM-MAIN@bama.ua.edu > Subject: Re: DFHSM question concerning Duplex copies > > From the HSM Guide: > The alternate tape must have the same tape geometry as the original. For > example, if the original tape is a 3590-1 tape, the alternate must be > > also. > > > The question is: Is the tape geometry of the 9840A and 9840D the same? > > Allan, is your Duplex parameter defined as follows: > SETSYS DUPLEX(MIGRATION(Y ERRALT(MARKFULL))) > > That would explain your following comment: > Whichever tape is > shorter will cause the initial primary/duplex pair to be marked full and > a new pair created. > > In my environment any problem with the duplex tape results in the > function (Migrate, Backup or Recycle) continuing and an HSM internal > Tapecopy task for each unduplex'd tape. > > Dave O'Brien > NIH Contractor > ________________________________________ > From: IBM Mainframe Discussion List [ibm-m...@bama.ua.edu] On Behalf Of > Staller, Allan [allan.stal...@kbm1.com] > Sent: Thursday, May 28, 2009 3:03 PM > To: IBM-MAIN@bama.ua.edu > Subject: Re: DFHSM question concerning Duplex copies > > This is actually the standard way duplexing works. Data is written > simultaneously to both the primary and duplex copy. Whichever tape is > shorter will cause the initial primary/duplex pair to be marked full and > a new pair created. > > Reading between the lines, it sounds like your management want's to use > (e.g.) 1 primary (long) and 2 duplex (short) to make up a primary/duplex > pair. This cannot be done. A 1 for 1 relationship between primary and > duplex volumes is mandatory. > > IIRC, the primary/duplex pair must be the same device type as well. As > stated above, the "shorter" tape controls. > > HTH, > > <snip> > Is there a way to fool HSM into using only part of a tape for ML2 and > Backup so that a shorter tape could be used for duplexing? > > We currently use 9840A drives for both local and remote (Duplex) ML2 and > Backup tapes. > Management would like to transfer the local HSM workload to an SL8500 > with 9840D tape drives. > Both the 9840As and 9840Ds are gen'd as emulated 3490s. > > We currently use the following Tapeutilization parameters: > > SETSYS - > TAPEUTILIZATION(UNITTYPE(L9840) PERCENTFULL(2200)) - > TAPESPANSIZE(1000) > SETSYS - > TAPEUTILIZATION(UNITTYPE(R9840) PERCENTFULL(2200)) - > TAPESPANSIZE(1000) > > </snip> > > ---------------------------------------------------------------------- > 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 > > ---------------------------------------------------------------------- > 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 > > ---------------------------------------------------------------------- > 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 > > ---------------------------------------------------------------------- > 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 > ---------------------------------------------------------------------- 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
