IBM Mainframe Discussion List <[email protected]> wrote on 06/17/2009 09:04:27 PM:
> Ed wrote on 18/06/2009 03:45:32 AM: > > > I would not write to tape. I would write several 3390s in parallel to > > take advantage of SAD "striping" support. Very little hassle and keeps > > down-time to a minimum. > > Last time I tried it, it took "a few" - I killed it after about 5 or 6 I > think. And that was *after* it had filled all my disk allocation. > SAP can be such a ... > > This was a test (developers) environment, so I could afford a reasonable > amount of time, and wanted to get the total dump. Never did anyway as it > turns out - > tape == looooong dump time. > > As for SL tapes - don't go there; especially if the tapes are known to a > library and/or tape management software. I used to isolate some carts, > re-init them as NL, and stick them in a box in the corner. Just hope they > never get used. SADMP IPL tapes and output tapes must be NL. SADMP has never supported SL tapes. SADMP can be relatively slow while it is reading paged out stuff from the MVS page data sets. Dumping data in real storage can be fairly fast if you have a high performance output configuration (like current top-of-the line DASD, 4 gigabit FICON channels/switches/DASD interfaces, and a multivolume output data set spread over a sufficient number of DASD subsystems and channels. With such a configuration using z/OS 1.10 on a z9 processor, SADMP was able to dump real storage dump at a bit over 300MB per second, at which point it became CPU bound. I have done considerable work in z/OS 1.11 to reduce the CPU bottleneck (using MIDAWs, cache prefetching, other path length reductions), and recently measured z/OS 1.11 on a z10 processor dumping real storage at over 1200MB per second to a 16 volume (and well spread out) data set. Jim Mulder z/OS System Test IBM Corp. Poughkeepsie, NY ---------------------------------------------------------------------- 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
