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Path: euryale.cc.adfa.oz.au!newshost.carno.net.au!harbinger.cc.monash.edu.au!munnari.OZ.AU!news.ecn.uoknor.edu!feed1.news.erols.com!howland.erols.net!vixen.cso.uiuc.edu!newsfeed.internetmci.com!news.uoregon.edu!Symiserver2.symantec.com!news From: tedm@agora.rdrop.com Newsgroups: comp.unix.bsd.freebsd.misc Subject: Re: whats a good external SCSI tape? Date: 24 Oct 1996 03:41:17 GMT Organization: Symantec Corp. Lines: 41 Message-ID: <54mogt$b3e@Symiserver2.symantec.com> References: <DzHp5B.6Bt.G.nanguo@nanguo.chalmers.com.au> <54dhae$3gs@uriah.heep.sax.de> <54j67v$soq@newsbr.eunet.fr> Reply-To: tedm@agora.rdrop.com NNTP-Posting-Host: shiva1.central.com X-Newsreader: IBM NewsReader/2 v1.2.5 In <54j67v$soq@newsbr.eunet.fr>, Frederic.Marand@osinet.fr (Frederic MARAND) writes: >j@uriah.heep.sax.de (J Wunsch) wrote: > >>Tandberg 2.5 GB QIC are fine (the latter is for those like me who find >>helical scan to be inherently horrible :). >It seems many people dislike helical scan backup units, but I never >could figure out why: we've sold tons of them, even to customers It is because it is darn near impossible to move tapes from one unit to another. I used to work for a large software company, we had 10 Exabyte 8mm drives (the older full-height ones) some compressing 5GB, some normal 5GB, and some 2GB. We used the drives on a daily basis for backing up our servers. These drives were all purchased from different vendors, at different times. I did updgrade all of them with current flash code, or ROMS. I could never get reliable restores unless I used the same tape in the same drive that it was created. I could re-use a tape in a different tape drive if I was doing a full overwrite of the data on there no problem. And, this was all same manufacturer-produced drives! I put it all down to minute alignment differences between the heads of the drives. We also had a number of 4mm units of various manufacturers that we used on the non-production "MIS play with" servers. Not only could I not get tapes created in one to be read by another reliably, I couldn't get them to be read at all! Worse, some drives had a nasty habit, if I stuck a tape in there and wrote to it, I could never ever use that tape again in any other drive, it HAD to be used in THAT particular drive. It's like the drive wrote some identifying leader to the tape that made all the other drives reject the tape. In contrast, with the QIC 150 tape drives I could read everyone's tapes in every other drive with no problem. I could tar off an archive at home on my Wangtek drive, read it at work on a Tandberg drive, use it on some other server with a Archive drive, etc. etc. Your customers probably use just ONE drive with ONE server and never have to deal with this kind of junk.