Mike, Have you confirmed with each DASD vendor that the contents of the channel command generated by TRKFMT ERASDATA are actually passed to the disk drive for drive types, parity schemes and volume formats?
To paraphrase your description, TRKFMT writes fulltrack records to cache then an empty track record to cache. The empty track record is all that makes it to the physical disk drives. In the case of Hitachi Dynamic Pools (HDP), if you erase a whole 38MB chunk like this there is nothing destaged and the chunk goes back in the free pool. Ron > -----Original Message----- > From: IBM Mainframe Discussion List [mailto:IBM-MAIN@LISTSERV.UA.EDU] > On Behalf Of Mike Schwab > Sent: Thursday, December 13, 2012 9:05 AM > To: IBM-MAIN@LISTSERV.UA.EDU > Subject: Re: [IBM-MAIN] dsf to write over entire volume > > I specified a headrange of 16 tracks. It does not issue an error message for > too many tracks, it writes on all 15 tracks in every cylinder, all cylinders are > written on (based on time (45 minutes/ > MOD3) and cylinder count). What TRKFMT does is write fulltrack records of > all B'00', B'11', and B'10' then an empty track record, per a ETR question > about 10 years ago. > > ICKDSF - MVS/ESA DEVICE SUPPORT FACILITIES 17.0 TIME: 23:37:02 > > TRKFMT ERASEDATA HEADRANGE(0,15) CYCLES(1) UNIT(3A0A) > VERIFY(ZZ3A0A) ICK00700I DEVICE INFORMATION FOR 3A0A IS CURRENTLY > AS FOLLOWS: > PHYSICAL DEVICE = 3390 > STORAGE CONTROLLER = 2105 > STORAGE CONTROL DESCRIPTOR = E8 > DEVICE DESCRIPTOR = 0C > ADDITIONAL DEVICE INFORMATION = 48000035 > TRKS/CYL = 15, # PRIMARY CYLS = 10017 ICK04000I DEVICE IS IN SIMPLEX > STATE ICK00091I 3A0A NED=002105.000.IBM.75.000000029651 > ICK03091I EXISTING VOLUME SERIAL READ = ZZ3A0A ICK00001I FUNCTION > COMPLETED, HIGHEST CONDITION CODE WAS 0 > 01:56:39 08/30/12 > > About 2 hours 20 minutes per Mod 9 IBM ESS 800 72GB Raid-5 6+P+S. > Erasing 2 volumes at once on an 8-pack would slow each volume to about > 3.5 vs 4.6 hours one at a time. > Erasing 3 volumes at once slowed each volume so much it did not result in > any decreased elapsed time. > Erasing 1 volume on 20 8-packs at once over 8 ESCON cables did not result in > slow downs. > Speed for other DASD devices I erased had different timings and will vary for > you. > > On Thu, Dec 13, 2012 at 9:44 AM, Ron Hawkins <ronjhawk...@sbcglobal.net> > wrote: > > Mike, > > > > While this will erase the logical track presented to a CKD host, it > > does not actually erase the data on the physical drive. > > > > You need to use the vendor's secure erase facility if the controller > > has one, or actually overwrite the whole volume with your favorite > > data generation or copy utility if you want to erase the contents from > > the physical disk drive. > > > > Ron > > -- > Mike A Schwab, Springfield IL USA > Where do Forest Rangers go to get away from it all? > > ---------------------------------------------------------------------- > For IBM-MAIN subscribe / signoff / archive access instructions, send email to > lists...@listserv.ua.edu with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
