Round tape reels! Now, that is old. Since I remember them too, we are both showing our age. Do you remember when the 200 bpi density?
Regards, Richard Schuh ________________________________ From: The IBM z/VM Operating System [mailto:IBMVM@LISTSERV.UARK.EDU] On Behalf Of Tom Huegel Sent: Wednesday, March 30, 2011 8:37 PM To: IBMVM@LISTSERV.UARK.EDU Subject: Re: DDR Question Slight brain fart, I didn't even think of hardware compression duh! I guess the only real way to to do it is just experimentation. I still seem to remember a program from long ago, and it may have been a VSE program, that would tell you how many bytes would go to the tape, in fact I think it told you how many feet of tape (2400/3400) would be used.. Thanks guys. On Wed, Mar 30, 2011 at 5:14 PM, Tom Duerbusch <duerbus...@stlouiscity.com<mailto:duerbus...@stlouiscity.com>> wrote: If you are doing software compression, then, perhaps use the Pipe DDR stage and route it to the "count" stage. But knowing how much compression the hardware will do....not obvious to me. However, once you do have a compressed tape, DITTO TMP will tell you how much tape the compressed dataset took on the media. Tom Duerbusch THD Consulting >>> Rich Greenberg <ric...@panix.com<mailto:ric...@panix.com>> 3/30/2011 4:55 >>> PM >>> On: Wed, Mar 30, 2011 at 11:37:00AM -0700,Tom Huegel Wrote: } That doesn't show the compressed byte count is (would be). The goal here is } to be able to predict how many tapes I will need to do backups. If you are doing hardware compression in the tape drive, I don't think there is any way for DDR to know the compressed byte count. Software compression, yes it would. I suspect that the easiest way to determine the tape counts will be experimentally. -- Rich Greenberg Sarasota, FL, USA richgr atsign panix.com<http://panix.com> + 1 941 378 2097<tel:%2B%201%20941%20378%202097> Eastern time. N6LRT I speak for myself & my dogs only. VM'er since CP-67 Canines: Val, Red, Shasta, Zero & Casey (At the bridge) Owner:Chinook-L Canines: Red & Cinnar (Siberians) Retired at the beach Asst Owner:Sibernet-L
