Date: Wed, 3 Apr 1996 12:33:13 +0930 (CST) From: Michael Smith <msmith@atrad.adelaide.edu.au> To: lehey.pad@sni.de (Greg Lehey) Cc: msmith@atrad.adelaide.edu.au, john@starfire.mn.org, questions@FreeBSD.ORG Subject: Re: looking for large-capacity tape recommendations, discommendations, comments Message-ID: <199604030303.MAA17834@genesis.atrad.adelaide.edu.au> In-Reply-To: <199604020941.LAA16321@nixpbe.pdb.sni.de> from "Greg Lehey" at Apr 2, 96 10:22:10 am
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Greg Lehey stands accused of saying: > > 4mm tape (DDS) go to 4 GB uncompressed (DDS-2 with 120 m cassettes). > All DDS-2 drives I know of offer compression, which in my experience > gives about 90% more storage (i.e. 7.2 GB), though this is strongly > dependent on the data (gzipped archives take up more space than > uncompressed data of the same size). People *have* claimed that DDS-2 > will offer up to 16 GB, and that DDS-1 (90m tapes, 2 GB uncompressed) > will offer up to 8 GB, but that's so far from normal experience that I > would consider it a lie. Well, we have a DDS-2 drive without compression. Lots cheaper, and most of the stuff we're backing up is either compressed or not amenable to DDS-style compression (raw radar data is pretty good as 'random noise'). > Over here, it's DM 10 for a 90m/4GB DDS-1 tape, and DM 28 for a 120m/8 > GB DDS-2 tape, both figures compressed. Compare these prices to, say, > DM 25 for a QIC-525 tape (520 MB), and the DDS-2 prices don't look > that bad. Pricing here is AUS$13 for a 90m tape, and AUS$45 for a 120m tape, and the 120m tapes are almost impossible to source. (Everyone 'has' them, but nobody can get stock). > > The Sony SDT-7000 would be a good buy in that category; it's claimed > > to be capable of over 700K/sec to/from the media (uncompressed) - > > we see around 400K/sec on an SDT-5200 here, and have been very > > happy with it. > > How long have you been running it? BTW, the HP C1533 seems to run at > about the same speed. We've had the 5200 about 8 months now; we do weekly backups and occasional (every couple of weeks) heavy runs with foreign tapes. So far it's run like a trooper. > > Exabytes can be temperamental, but well-kept they're very reliable. > > So I've been told. I have one (several 8200's, only one working) at home; as long as you put up with its idiosyncracies (and the _wonderful_ range of funny noises it makes), it's not so bad. Getting them fixed is a nightmare though 8( > Greg -- ]] Mike Smith, Software Engineer msmith@atrad.adelaide.edu.au [[ ]] Genesis Software genesis@atrad.adelaide.edu.au [[ ]] High-speed data acquisition and (GSM mobile) 0411-222-496 [[ ]] realtime instrument control (ph/fax) +61-8-267-3039 [[ ]] Collector of old Unix hardware. "Where are your PEZ?" The Tick [[
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