> -----Original Message----- > From: The IBM z/VM Operating System > [mailto:[EMAIL PROTECTED] On Behalf Of Stracka, James (GTS) > Sent: Friday, June 06, 2008 10:36 AM > To: IBMVM@LISTSERV.UARK.EDU > Subject: Re: Backup: Twinning Tapes to Remote Tape Unit > > Now that is interesting. How does that OS/390 utility know where the > EOT reflector is located unless it spins the entire tape first?
Well, it doesn't really __know__. It does know the approprimate length of the tape from a sense command. The drive "knows" what type of tape medium is mounted on it. It then estimates how many blocks it should write. The 3490 and later drives will tell, via a sense command, the current block id (this accounts for compression on the drive). When the current block id is greater than the estimate, then the utility does an FEOV to force an end-of-volume switch. -- John McKown Senior Systems Programmer HealthMarkets Keeping the Promise of Affordable Coverage Administrative Services Group Information Technology The information contained in this e-mail message may be privileged and/or confidential. It is for intended addressee(s) only. If you are not the intended recipient, you are hereby notified that any disclosure, reproduction, distribution or other use of this communication is strictly prohibited and could, in certain circumstances, be a criminal offense. If you have received this e-mail in error, please notify the sender by reply and delete this message without copying or disclosing it.
