Skip, On FICON it would be reasonable to expect to get 50MB/sec to and from your Disk and tape drives. I know FICON can go faster (I've run 377MB/sec through a FX4 port), but you'll normally have to share with all the other traffic in the SAN, disk, and tape units. 50MB/sec would be a reasonable number for planning.
So 54,000MB at 50MB/sec is 1080 seconds, or 18 minutes. Shadowimage, Timefinder and Flashcopy give you some faster alternatives. Ron > -----Original Message----- > From: IBM Mainframe Discussion List [mailto:[EMAIL PROTECTED] On > Behalf Of Skip Robinson > Sent: Friday, February 08, 2008 9:28 AM > To: [email protected] > Subject: Re: [IBM-MAIN] VTOC size > > The idea of massive volumes is intriguing, but my concern would be > backup/restore. On some our non-z platforms we have huge volumes many > times > the size of 3390-3. When one of them went south a while back, it took > hours > and hours to get it restored. With RAID arrays, of course, that's not > supposed to happen; I think it was a problem with an SVC. > > On the mainframe we take frequent full volume backups. The likelihood > of > true failover (DR) is minuscule, and we use XRC mirroring for that > contingency anyway. On the other hand the probability of having to > retrieve > an accidentally deleted or modified file is huge--it happens all the > time > even for sysprog finger checks. > > 1. How long does it take to make a tape backup of a 32760 cylinder > volume? > 2. Where does that backup live? > 3. How long does it take to restore a critical 10 track file from two > weeks > ago that happens to live on the corner of cylinder 31753? > > . > . > JO.Skip Robinson > Southern California Edison Company > Electric Dragon Team Paddler > SHARE MVS Program Co-Manager > 626-302-7535 Office > 323-715-0595 Mobile > [EMAIL PROTECTED] > > > > "Van Dalsen, > Herbie" > <Herbie.VanDalsen > To > @ELAVON.COM> [email protected] > Sent by: IBM > cc > Mainframe > Discussion List > Subject > <[EMAIL PROTECTED] Re: VTOC size > .EDU> > > > 02/08/2008 05:46 > AM > > > Please respond to > IBM Mainframe > Discussion List > <[EMAIL PROTECTED] > .EDU> > > > > > > > Mark, > > I suppose that you have already got the answers that you wanted, This > is > just an alternate idea. > > When we initialized our Shark array's in 2004, we create a few with > 1113 > cylinders, a few 10017 and most 3339 cylinders. > > The last two we installed, we had mainly 32760 Cylinder volumes, about > 10 10017's and 2 3339's , 1 1113 and a 848 which we use to contain only > the master catalog, and nothing else. > > The logic is this... In SMS allocation of small datasets goes to the > M1's medium to the M3/M9's and The massive VSAMS / IAM's to M27's > > We have never had a major problem where our VTOCs were full before the > volumes, and this is the sizes... > > M1 = INDEX(0,1,1) VTOC(0,2,15) > M3 = INDEX(0,1,7) VTOC(0,8,75) > M9 = INDEX(0,1,7) VTOC(0,9,75) > M27 = INDEX(0,1,4) VTOC(0,5,75) > > Regards > > Herbie > > ---------------------------------------------------------------------- > 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 ---------------------------------------------------------------------- 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
