From owner-freebsd-questions Tue Apr 2 03:18:01 1996 Return-Path: owner-questions Received: (from root@localhost) by freefall.freebsd.org (8.7.3/8.7.3) id DAA06417 for questions-outgoing; Tue, 2 Apr 1996 03:18:01 -0800 (PST) Received: from nixpbe.pdb.sni.de (mail.sni.de [192.109.2.33]) by freefall.freebsd.org (8.7.3/8.7.3) with ESMTP id DAA06404 for ; Tue, 2 Apr 1996 03:17:53 -0800 (PST) Received: (from nerv@localhost) by nixpbe.pdb.sni.de (8.6.12/8.6.12) id LAA16326 for questions@FreeBSD.ORG; Tue, 2 Apr 1996 11:42:02 +0200 Message-Id: <199604020942.LAA16326@nixpbe.pdb.sni.de> Subject: Re: looking for large-capacity tape recommendations, discommendations, comments To: msmith@atrad.adelaide.edu.au (Michael Smith) Date: Tue, 2 Apr 96 10:22:10 MET DST From: Greg Lehey Cc: john@starfire.mn.org, questions@FreeBSD.ORG In-Reply-To: <199604020137.LAA08733@genesis.atrad.adelaide.edu.au>; from "Michael Smith" at Apr 2, 96 11:07 am X-Mailer: xmail 2.4 (based on ELM 2.2 PL16) Sender: owner-questions@FreeBSD.ORG X-Loop: FreeBSD.org Precedence: bulk > > john@starfire.mn.org stands accused of saying: >> >> I am looking for recommendations and user experience with large- >> capacity (14Gb+) 4mm tape drives. These are fairly costly items, > > 14G? No such animal. 4mm tape drives go to 4GB. 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. > 4G media are more than twice as expensive as 2G media; unless you > have a pressing need to put 4G on a single tape the only > justification for buying a DDS-2 drive is extra speed. Not so. I do a nightly backup of 8 GB on one machine. With DDS-2, I just do the backup. With DDS-1, I'd have to get up in the middle of the night to change the tape. Yes, the cartridges are more expensive. 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. > 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. >> and we want to make sure that we get one that we'll be happy with >> the first time. I know that Exabyte 8500's are pretty good, but >> of course, that's an 8mm drive. > > Exabytes can be temperamental, but well-kept they're very reliable. So I've been told. Greg