In a message dated 6/29/2005 3:44:51 P.M. Central Daylight Time, [EMAIL PROTECTED] writes:
>From the mainframe CCW point-of-view, once you write over a track, the previous contents are no longer recoverable. Yep yep yep. 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. But with clever programming many, many such tracks can be erased simultaneously on different devices. The OP was concerned about security in a DR situation and not top secret clearance sanitizing the data so that even Mission Impossible people couldn't read it. Bill Fairchild ---------------------------------------------------------------------- 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
