From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on inbox.vuxu.org X-Spam-Level: X-Spam-Status: No, score=-0.3 required=5.0 tests=DKIM_ADSP_CUSTOM_MED, DKIM_INVALID,DKIM_SIGNED,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,HTML_MESSAGE,MAILING_LIST_MULTI, RCVD_IN_DNSWL_NONE autolearn=ham autolearn_force=no version=3.4.2 Received: from minnie.tuhs.org (minnie.tuhs.org [45.79.103.53]) by inbox.vuxu.org (OpenSMTPD) with ESMTP id 00577b6c for ; Mon, 25 Nov 2019 21:09:06 +0000 (UTC) Received: by minnie.tuhs.org (Postfix, from userid 112) id A28469C623; Tue, 26 Nov 2019 07:09:04 +1000 (AEST) Received: from minnie.tuhs.org (localhost [127.0.0.1]) by minnie.tuhs.org (Postfix) with ESMTP id BE68493D74; Tue, 26 Nov 2019 07:08:36 +1000 (AEST) Authentication-Results: minnie.tuhs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.b="hZJsVTCe"; dkim-atps=neutral Received: by minnie.tuhs.org (Postfix, from userid 112) id 4D12B93D74; Tue, 26 Nov 2019 07:08:34 +1000 (AEST) Received: from mail-vk1-f170.google.com (mail-vk1-f170.google.com [209.85.221.170]) by minnie.tuhs.org (Postfix) with ESMTPS id C0F3893D71 for ; Tue, 26 Nov 2019 07:08:33 +1000 (AEST) Received: by mail-vk1-f170.google.com with SMTP id r4so3839802vkf.9 for ; Mon, 25 Nov 2019 13:08:33 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=lQWUqxyIRO1vB1zYjyImXmCqI1m5+e+qXaZ7/fbmVS4=; b=hZJsVTCeIydtSRYmu8X7XgS4/6qEvLOUsCvsnhAvKCa+xDCJQOw+vtnJ3V44FB9BJA cYZOa66SI2Vl/xA2HyqPuFVRGQAyCP9F5np8yl379DV6ihOK4dQr9+ZIBGCJirjyMxIP sRab5fdleCgPqwEGIo1x0nvcE9+4MaiQkQoCxEM2pPAm8AvjVtAegXtv1LaiH6B1MWG7 WAtyFENMKRbBOcfxdher9A3OezrhrhipYJTuKewDSRakWv/FFrGtAUC94Hf86qArK4fz jziYyAu6NxX9hU6B8rAS14c82hLZZLe4Ei+2465paO8CcvoOCQ5VZx+syeaZAfHMlMJe EWuA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=lQWUqxyIRO1vB1zYjyImXmCqI1m5+e+qXaZ7/fbmVS4=; b=IVYYuw4BtbUTQx5KKUFadjIk/Xkb+6Welztz2dJuZdvwNBrDqQ6q8vgGT5I2M/kYo7 WrlQgEGCDky3fkmVMzteABw8QG1fJk55Xz7Hu91kcqNKkszuoaY6XyarX+KDZq8JZCjl oefG3wSNb05WQPffyar6nEHwOPE9PCRVhX/43t5ULOOUoAMGTlSfhl9+zwSICEf3QXVt /0HVxuqyGB37OGXyhRXjvwJPtRHFeCh1LlJkfbFzKyA2AjXcQD9znPwNTy1YZIIJE/cD zUEfsY8Hs9AfT7T+9yM0zkTed4E9cC62r7LnkSLDGrEwowZouEiS+0NLOUGfAK2zDsDA pYow== X-Gm-Message-State: APjAAAXQNoiYfrAWqaJQMW8l/0fGDAqolQqxu5g9Wfi9sCJNMi4DF+vy axIYm2Dc3xvvC8GHxVM19zKs9NQhR3A8Y7FzRnFCWCL5 X-Google-Smtp-Source: APXvYqxHbeBNMEjilmGMWuwSmJItZXB5Aa1qiB+8CyAAxSgbxj9PGrQo3zCwZRiQS+pgeRwFnBptqIN7GZ6GznKaFSw= X-Received: by 2002:a05:6122:1181:: with SMTP id x1mr15701695vkn.25.1574716112589; Mon, 25 Nov 2019 13:08:32 -0800 (PST) MIME-Version: 1.0 References: <20191124225239.GG18200@mcvoy.com> <20191125032404.GM18200@mcvoy.com> <0a6fb097-fe79-1633-0205-1c45f0a56953@bitsavers.org> <96b55e5e-4b05-f7b7-c2ae-efdae7c18b2f@kilonet.net> <20191125174515.GY18200@mcvoy.com> <320e0de3-3bb5-4839-c209-1947efc89fdb@kilonet.net> In-Reply-To: <320e0de3-3bb5-4839-c209-1947efc89fdb@kilonet.net> From: "John P. Linderman" Date: Mon, 25 Nov 2019 16:08:20 -0500 Message-ID: To: Arthur Krewat Content-Type: multipart/alternative; boundary="000000000000835b950598322af1" Subject: Re: [TUHS] Someone wants to use an exabyte X-BeenThere: tuhs@minnie.tuhs.org X-Mailman-Version: 2.1.26 Precedence: list List-Id: The Unix Heritage Society mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: The Unix Heritage Society Errors-To: tuhs-bounces@minnie.tuhs.org Sender: "TUHS" --000000000000835b950598322af1 Content-Type: text/plain; charset="UTF-8" I'm not an expert on mag tapes, but it makes sense to me that 9-track tapes, where the tracks "line up" when the tape is wound onto a reel, suffer more "print-through" than helical scan tapes, where tracks are not aligned with those under them on a reel. I recall a suggestion that 9-track tapes should be mounted and rewound once in a while, to reduce print-through. We used Exabytes for disk backups for years, back when tape capacity exceeded disk capacity. I doubt I'll see that again, but, as noted I'm not an expert on mag tapes. On Mon, Nov 25, 2019 at 1:35 PM Arthur Krewat wrote: > On 11/25/2019 12:45 PM, Larry McVoy wrote: > > On Mon, Nov 25, 2019 at 12:40:22PM -0500, Arthur Krewat wrote: > >> PS: DAT 4mm tape drives, especially whatever Sun was using, were awful. > > It's no secret that I enjoyed my years at Sun, but I can't defend these > > drives, I had the same experience. When I look back on it, the only > > tapes that I remember being reliable where the 9 track reel to reel > > and the QIC-150. Once it got to GB sized tapes, everything seemed > > like crap. > > > > The Exabyte 5GB and up stuff was pretty good. LTOs, after having worked > with them for the past 13 years, I can definitely say, are quit awesome. > > DLT tapes and especially robots, well, it took HP about 5 years to get > the firmware right for a certain robot, the model of which, I don't > recall ... > > art k. > > --000000000000835b950598322af1 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
I&#= 39;m not an expert on mag tapes, but it makes sense to me that 9-track tape= s, where the tracks "line up" when the tape is wound onto a reel,= suffer more "print-through" than helical scan tapes, where track= s are not aligned with those under them on a reel. I recall a suggestion th= at 9-track tapes should be mounted and rewound once in a while, to reduce p= rint-through. We used Exabytes for disk backups for years, back when tape c= apacity exceeded disk capacity. I doubt I'll see that again, but, as no= ted I'm not an expert on mag tapes.

On Mon, Nov 25, 2019 at 1:35 P= M Arthur Krewat <krewat@kilonet.ne= t> wrote:
On 11/25/2019 12:45 PM, Larry McVoy wrote:
> On Mon, Nov 25, 2019 at 12:40:22PM -0500, Arthur Krewat wrote:
>> PS: DAT 4mm tape drives, especially whatever Sun was using, were a= wful.
> It's no secret that I enjoyed my years at Sun, but I can't def= end these
> drives, I had the same experience.=C2=A0 When I look back on it, the o= nly
> tapes that I remember being reliable where the 9 track reel to reel > and the QIC-150.=C2=A0 Once it got to GB sized tapes, everything seeme= d
> like crap.
>

The Exabyte 5GB and up stuff was pretty good. LTOs, after having worked with them for the past 13 years, I can definitely say, are quit awesome.
DLT tapes and especially robots, well, it took HP about 5 years to get
the firmware right for a certain robot, the model of which, I don't recall ...

art k.

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