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> As to why you were able to put a 13.7GB data set onto a 8GB tape? Ya got > me. default compression. our 8mm does 1 tape for approx 15 gig jim franz ----- Original Message ----- From: "John Earl" <johnearl@powertechgroup.com> To: <midrange-l@midrange.com> Sent: Tuesday, January 15, 2002 1:49 AM Subject: Re: DUPTAP command > Neil, > > Just a guess, but tape is an inherently slower media than disk so your > (time) results actually make sense to me... > > SAV = 4.5 Hours > DUP = 6+ hours > RST = 3.25 hours. > > The SAV is reading from fast disk and writing to slow tape. There is a > verify process with each block of data written, so it stands to reason that > it would take longer to SAV where you read from fast disk and write to slow > tape than it takes RST where you read from slow tape and write to fast disk. > > During the DUP process you are reading from slow tape and writing to slow > tape. With all those reads, writes, verifies and tape repositions, it's > just going to take a lot longer. > > As to why you were able to put a 13.7GB data set onto a 8GB tape? Ya got > me. > > jte > > > > > > ----- Original Message ----- > From: "Neil Palmer" <NeilP@DPSlink.com> > To: <midrange-l@midrange.com> > Sent: Monday, January 14, 2002 7:39 AM > Subject: DUPTAP command > > > > OK - more a story for comment than a specific question, but I could ask > > why does the DUPTAP command take so bl**dy long ? > > > > Backed up all user data on an old model 400 (CPW 20.6) Friday night, to a > > single 8mm 7/14GB tape (wrote 13.7GB to tape) on an internal 6390 8mm > > drive. Took just under 4.5 hours to do the complete save. > > Saturday morning went to a model 270 (with CPW 950) to do DUPTAP from 8mm > > to an SLR5-4gb (4/8GB tape) on a 6382 QIC drive, reading from a 7208-342 > > 8mm drive. DUPTAP took just over 6 hours !! Also, weird thing is we kept > > waiting for message to change QIC tape after about 8GB, but the message > > never came. It actually wrote all 13.7GB to a single 4/8GB tape (in > > format QIC4DC). ??? > > Then back to new model 270 (CPW 150) with a 6386 QIC drive to reload all > > user data. This managed to read the entire tape and restore all the data > > in just under 3.25 hours ! > > > > It makes absolutely no sense to me why DUPTAP takes so long to run - even > > longer than to run the actual save or restore jobs on much slower systems > > (although the restricting speed is no doubt the write speed to an SLR5-4GB > > tape, not the CPW of the box). Anyone else have any annoying experiences, > > or knowledge, on this stupid command ? ;-) > > > > ...Neil > > _______________________________________________ > > This is the Midrange Systems Technical Discussion (MIDRANGE-L) mailing > list > > To post a message email: MIDRANGE-L@midrange.com > > To subscribe, unsubscribe, or change list options, > > visit: http://lists.midrange.com/cgi-bin/listinfo/midrange-l > > or email: MIDRANGE-L-request@midrange.com > > Before posting, please take a moment to review the archives > > at http://archive.midrange.com/midrange-l. > > > > _______________________________________________ > This is the Midrange Systems Technical Discussion (MIDRANGE-L) mailing list > To post a message email: MIDRANGE-L@midrange.com > To subscribe, unsubscribe, or change list options, > visit: http://lists.midrange.com/cgi-bin/listinfo/midrange-l > or email: MIDRANGE-L-request@midrange.com > Before posting, please take a moment to review the archives > at http://archive.midrange.com/midrange-l. > >
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