From owner-freebsd-hardware Wed Apr 7 20:21:50 1999 Delivered-To: freebsd-hardware@freebsd.org Received: from pyramid.interdomain.net.au (pyramid.interdomain.net.au [203.17.167.4]) by hub.freebsd.org (Postfix) with SMTP id 3B212151F1 for ; Wed, 7 Apr 1999 20:21:40 -0700 (PDT) (envelope-from rha@interdomain.net.au) Received: (qmail 3112 invoked from network); 8 Apr 1999 03:19:33 -0000 Received: from unknown (HELO ?203.17.167.17?) (203.17.167.17) by pyramid.interdomain.net.au with SMTP; 8 Apr 1999 03:19:33 -0000 Message-Id: In-Reply-To: <19990408135519.B1051@lucy.cs.waikato.ac.nz> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Date: Thu, 8 Apr 1999 13:19:21 +1000 To: freebsd-hardware@FreeBSD.ORG From: Richard Archer Subject: Re: DDS-2/DDS-3 drives Sender: owner-freebsd-hardware@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org At 11:55 +1000 8/4/1999, Joerg Micheel wrote: >For some project people here are interested to own a DDS tape drive. I do have >no experience with these drives and would be interested in any stories you >may have to tell about how reliable they are, how well they work with >FreeBSD (or other OS: Solaris, Linux), what tapes may cause trouble etc. >You may respond privately, unless it is of general interest. DDS drives have given me the greatest grief of any computer component I have used. DAT is a helical scan technology, great for domestic VCR and audio. But wrapping a 4mm tape around a spinning head and trying to hold it in alignment is practically impossible. This makes DDS unreliable and hence inappropriate for use as a backup medium. I've had similar problems with Exabyte (8mm helical scan), and I swear I will never purchase another helical scan backup device. DLT (for example) is a technology that's designed specifically for data. The heads are fixed (well, they step up and down to read/write different tracks and they are micro-adjustable for automatic alignment calibration), and the data is written to the tape in end-to-end parallel tracks. The tape is run reel-to-reel, and it's a much wider tape for added stability. I've been using DLT for 8 months, and with 1.5 TB written and verified, I've not lost any data yet. In the same time (same data... we're running parallel DAT and DLT backups while 'evaluating' DLT) I've lost 7 or 8 DAT tapes (and 2 drives). ...Richard. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hardware" in the body of the message