A re-write of HOME ADDRESS for each track, chaining together I/Os to logically reset 1 3380/3390 cylinder with each I/O might be sufficient in a DR situation where you can trust that the DASD will be reused soon and often before it gets removed. /Tom Kern
--- Bruce Black <[EMAIL PROTECTED]> wrote: > > > > > >For DR security purposes, format writing any kind of data will > >cause the rest of the track to be erased after the last block is written > >and, when read back by software on the mainframe, the original data will > not be > >readable. In this case it doesn't matter if you write two, three, 50, or > one > >block per track of only one byte long. What matters is you are doing > format > >writes, as would be the case with DISP=NEW. Still it will require one > whole > >revolution's worth of time for each track to be erased. > > > It doesn't necessarily require a revolution. Depending on how the disk > vendor has written their CKD emulation, it may simply be necessary to > write info at the beginning of the emulated CKD track (on the FBA disk) > indicating that there are no more records on the track. Residual data > may still exist on the rest of the emulated track, but there is no way > to access it from the mainframe. The only way to ensure the complete > overwrite is to write a full-track record. > > -- > Bruce A. Black > Senior Software Developer for FDR > Innovation Data Processing 973-890-7300 > personal: [EMAIL PROTECTED] > sales info: [EMAIL PROTECTED] > tech support: [EMAIL PROTECTED] > web: www.innovationdp.fdr.com > > ---------------------------------------------------------------------- > 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 > __________________________________ Yahoo! Mail Mobile Take Yahoo! Mail with you! Check email on your mobile phone. http://mobile.yahoo.com/learn/mail ---------------------------------------------------------------------- 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
