Date: Sat, 30 Jan 1999 03:07:11 +1100 From: jonathan michaels <jon@caamora.com.au> To: freebsd-questions@FreeBSD.ORG Subject: Re: Tape drive Message-ID: <19990130030711.A1712@caamora.com.au> In-Reply-To: <199901291501.KAA22170@cc942873-a.ewndsr1.nj.home.com>; from Crist J. Clark on Fri, Jan 29, 1999 at 10:01:36AM -0500 References: <19990129175337.D8473@freebie.lemis.com> <199901291501.KAA22170@cc942873-a.ewndsr1.nj.home.com>
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On Fri, Jan 29, 1999 at 10:01:36AM -0500, Crist J. Clark wrote: > Greg Lehey wrote, > > DDS and Exabyte are just plain too unreliable, though they're getting > > better. > > Greg, is this personal or anecdotal experience? Or can you point to > some references that bear this conclusion out? We use Exabyte a _lot_ > here at work and hearing this from you concerns me. Also, when you say > they are unreliable, are you talking about the media (properly written > tapes fail), the transfer (tapes do not get written/read properly), or > the hardware (the drives are in the shop to much)? the only exabytes i;m familiar with are 'refurbished by exabyte' here in australia the few that i have seen don't inspire confidance. refurbished ibm (sourced from emrald, oem'd by tandberg) after teh tdc-3660 that s teh ceramic-pemaloy head technology were very good indeed. mechanisms would last foe years, 10 years now being not uncommon. only probelms witht the tdc-3660 were teh permalloy heads .. if you used a poor quality abrasive tape you would chew a head out quiclly. about th eonly other real probelm is teh pinch roller and capstain. when a tape is inserted the capstain is engaged by teh pinchroller, if the tape was left in for any length of time teh pinchroller becme indented as did teh tape .. fortunately the qic, quarter inch format could easily recover from such a 'dat style fatal disaster' .. er problem. aboiut the only real problem witht he qic (the real quarter inch cartridges, not teh tinny 'colorado clones') was teh cost to install and the small capacities .. these have been larely overcome with several drives capable of writing 13 gb raw to qic-4??? tape at some 26 kb/sec this is what tendberg claims . my old tdc-3820 qic-525 claims 12 kb/sec and delivers 14 kb/sec on linux and interactive v3.?.? about 11 kb/sec on os2 v2 and v3, novell v3.11 and v3.12 .. i have yet to get it working reliably, if at all on freebsd. but i'm getting close. as far as cost teh 5 gb with onboard realtime compression (2.4 gb raw) cost about as much as an old 1 gb travan, new 4 gb travan .. all pretty much exploration on a colorado theme .. cheap consumer tape drives. yes tandberg used to make very good taperecorders .. they just moved this to data sortage where the requirements were far less stringent .. and got excelent results .. ok i'm biased. > > For daily backups, you might consider a small number of large > > IDE drives. They'll be fractionally more expensive in the short term, > > but cheaper in the long run, and they'll certainly back up faster. > > The problem I have with this solution is that it seems that you are > putting all your eggs in one basket. If that backup fails > catastrophically, you lose _all_ your backups at once. Seems that you > would have to backup your backups occasionally. So, you're still stuck > with doing tapes or some other media for the backup^2. not a problem with a qic tape drive > There probably is a procedure to get around this problem (or I may be > seeing a problem where there is not one), what is the prefered > procedure for using IDE drives for backup? buy a tandberg .. ok smile .. sort off, i got bitten once using a mirrored harddisk as teh backup storage system. it was a spare ide, i won't be doing that in a hurry. as i said, i've been using qic drives for over 6 years now and have yet to experience a flaw .. sure several tapes failed, buy cheap tape expect cheap tape to fail. from where i sit and unlike greg i don;t value a tape drive by what it cost to purchase. fro me teh equation is quite simple .. the cost/value of teh tape drive is teh contents of teh tape archive. i used to have several archives that were the results of many hundered od hours hard work now at some $AUD100 per hour this made teh initial cost of teh tandberg irrelevant. cost and articel value depend largely on where you sit on the fence, as i see it. regards jonathan -- =============================================================================== Jonathan Michaels PO Box 144, Rosebery, NSW 1445 Australia ===========================================================<jon@caamora.com.au> To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message
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