Xref: utzoo comp.sys.pyramid:246 comp.periphs:1194 Path: utzoo!utgpu!water!watmath!clyde!att!osu-cis!tut.cis.ohio-state.edu!bloom-beacon!bu-cs!purdue!decwrl!sun!pitstop!sundc!seismo!uunet!mcvax!inria!irisa!decouty From: decouty@irisa.UUCP (Bertrand Decouty) Newsgroups: comp.sys.pyramid,comp.periphs Subject: Re: S159 Cartridge tape Keywords: Reliability, helical scan recording Message-ID: <669@irisa.UUCP> Date: 21 Sep 88 14:16:28 GMT References: <459@Terra.cc.brunel.ac.uk> <40260@pyramid.pyramid.com> Organization: I.R.I.S.A., Rennes, Fr Lines: 38 In article <40260@pyramid.pyramid.com> csg@pyramid.pyramid.com (Carl S. Gutekunst) writes: [ text deleted] >While these drives are interesting, they are hardly a panacea. The big problem >is reliability. The drives are rated at "10,000 hours, 10% duty cycle," which ^^^^^^^^^^^ >means that to achieve a 10,000 hour life you cannot use the drive more than 2 >hours and 2 minutes per day. That's a little more than a gigabyte per day. If >you have more than that, the drive will wear out sooner. Sure enough, when we >ran the drives continuously, they died consistently in about two months. ^^^^^^^^^^^^ > >Could you be more precise, please? Is it 10% continuously or not? Because doing a back-up of 500 MBytes of a local disk on a Sun 3 can take as long as 1 hour but the same back-up of a *remote* disk take 3 times more! Which method is the best for big back-up (near a full tape, 1.7 GB for a 90mn tape): 3 hours continuously or 3 times 1 hour separated by 1 idle hour? (it is an example). Is there any people having such an experience of large and long back-up? It seems to me that many people are interested by Exabyte-like products but few people really uses it for more than 500 MB back-up, so we have no idea of real reliability: dump failure, hardware failure... Thanks for any info. ----- Bertrand DECOUTY @ INRIA-IRISA (Centre de Rennes) ----- +------------------------------+----------------------------------------------+ | IRISA - INRIA | EMAIL : decouty@irisa.fr | | Campus de Beaulieu | UUCP : {mcvax,inria!}irisa!decouty | | F-35042 Rennes Cedex | decouty@irisa.UUCP | | FRANCE | BITNET: DECOUTY@FRCICB71 | +--------------------------+---+--------------------+-------------------------+ | PHONE : +33 99 36 20 00 | TELEX : 950473 UNIRISA | FAX : +33 99 38 38 32 | +--------------------------+------------------------+-------------------------+