From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on inbox.vuxu.org X-Spam-Level: X-Spam-Status: No, score=-0.8 required=5.0 tests=DKIM_INVALID,DKIM_SIGNED, HTML_MESSAGE,MAILING_LIST_MULTI autolearn=ham autolearn_force=no version=3.4.4 Received: (qmail 15524 invoked from network); 27 Nov 2021 01:07:23 -0000 Received: from minnie.tuhs.org (45.79.103.53) by inbox.vuxu.org with ESMTPUTF8; 27 Nov 2021 01:07:23 -0000 Received: by minnie.tuhs.org (Postfix, from userid 112) id 8F5B99CEA6; Sat, 27 Nov 2021 11:07:19 +1000 (AEST) Received: from minnie.tuhs.org (localhost [127.0.0.1]) by minnie.tuhs.org (Postfix) with ESMTP id 5B45E9CE5D; Sat, 27 Nov 2021 11:04:44 +1000 (AEST) Authentication-Results: minnie.tuhs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=bsdimp-com.20210112.gappssmtp.com header.i=@bsdimp-com.20210112.gappssmtp.com header.b="PFOq6xPb"; dkim-atps=neutral Received: by minnie.tuhs.org (Postfix, from userid 112) id A25089CE5D; Sat, 27 Nov 2021 10:56:24 +1000 (AEST) Received: from mail-ua1-f42.google.com (mail-ua1-f42.google.com [209.85.222.42]) by minnie.tuhs.org (Postfix) with ESMTPS id D632A94942 for ; Sat, 27 Nov 2021 10:56:22 +1000 (AEST) Received: by mail-ua1-f42.google.com with SMTP id n6so21825713uak.1 for ; Fri, 26 Nov 2021 16:56:22 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bsdimp-com.20210112.gappssmtp.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=DLgInghMMJ47rz4MPEAs13B2enlVV6JD3APdU2gg8lE=; b=PFOq6xPbDL4AUIkyWPVELDw12J86jqmTpA0EYNqNFaq1xMvLBkHXyW030dUmkm3xy2 rtxi9eZpsPY9wYSF1R7no1K9Fv1r5Jf0OPIwedVtU5hb2boMG2Na2z9uiwu50yQ+3NYk tdUuZ118I4cyr53TCXpCnyEdKes3fXmfefegPBs9Uk8Z2/u0FbW9VbF+dsJmS19nv9IC t/pkrdWk4pzhPU4KsUSagtx3t0mKjd5X+GBIYQ7vp7CeWZBcjON9P+cZd8keDO1or0dR hRzexWu4StOBd1o7nk0RMEBElJHlg3i0Vfu1EoRnvgNHKsenudVjDO2MF5sYjpHh6+bD 97Lw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=DLgInghMMJ47rz4MPEAs13B2enlVV6JD3APdU2gg8lE=; b=P8t81+fvx+WuQw4FpD3UIGNB9pRDqMwPdCv7VBvI91yDSSBbVk269/p05PzIlX7s6b UBxfcFt/2zo9RV0eMGh3XUygyK1F6DJ2F1l4JnvGzxo9N1DvdtrqhRSWTk4xtKgvmWAX cYs8Gr1LXfazg/l8XwS0bmFWjwylu8sjWGrPDm0plctVukSTdW5+Yt+7Dt66Q2gYnSem rwgYIwGl6fH5Mpkwtlqaq/atCjWCntqkmMf6DV7XTUnpFoaf19MuSx+c7R6ATluHhAtg khsmlMWtmXy/6RHGTYw1N/oFK74oGe+vX7Vyk0yI2WNwnhLlQXBdYj8f06uehO9VzIQ7 3LVA== X-Gm-Message-State: AOAM532CS3x3rLZWx015Ap8uBNsTNnRfgflNHnOuG8Tm6AOBf5N9ToPp kENsS5OqTTWn1y1wOyzWseLfpu99eDbIq1QntvitSw== X-Google-Smtp-Source: ABdhPJzt0gx0ARKFZxlJ+NVoFXoB1gwqE03kpld8A7VDtmjv5eC6NvvnMetQYgQtYlRpztFglNIdjLfpvMFBrEJ8qn8= X-Received: by 2002:a67:ec8f:: with SMTP id h15mr21260765vsp.42.1637974581818; Fri, 26 Nov 2021 16:56:21 -0800 (PST) MIME-Version: 1.0 References: <0ABB7ECD-049B-4993-938F-82BC924E0F39@gmail.com> <20211127002307.C6E3A2B6CEC@yagi.h-net.msu.edu> <20211127003006.GK19525@mcvoy.com> In-Reply-To: <20211127003006.GK19525@mcvoy.com> From: Warner Losh Date: Fri, 26 Nov 2021 17:56:09 -0700 Message-ID: To: Larry McVoy Content-Type: multipart/alternative; boundary="00000000000019cc2e05d1baaddd" Subject: Re: [TUHS] PL/I stuff - was: Book Recommendation 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: TUHS main list Errors-To: tuhs-bounces@minnie.tuhs.org Sender: "TUHS" --00000000000019cc2e05d1baaddd Content-Type: text/plain; charset="UTF-8" On Fri, Nov 26, 2021, 5:32 PM Larry McVoy wrote: > On Fri, Nov 26, 2021 at 07:23:07PM -0500, Dennis Boone wrote: > > > In my experience 9 track tapes were not guaranteed to be readable > after > > > some interval. In fact, a standard operations procedure was to copy > > > important tapes to new media periodically. > > > > There are always ways in which your backups can go wrong and not be > > readable, and I'm not arguing that here. > > > > But 9 track tapes have turned out to be pretty spectacularly long-lived. > > I've personally read tapes that were stored for 30+ years in > > unconditioned spaces. > > Contrast that with the write only exabyte tapes. I lost some stuff to > those. > There is a reason that exabyte no longer exists. It used to take up a big swath of central Boulder. Warner > --00000000000019cc2e05d1baaddd Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable


On Fri, Nov 26, 2021, 5:32 PM Larry McVoy <lm@mcvoy.com> wrote:
On Fri, Nov 26, 2021 at 07:23:07PM -0500, Dennis Boone wr= ote:
>=C2=A0 > In my experience 9 track tapes were not guaranteed to be re= adable after
>=C2=A0 > some interval.=C2=A0 In fact, a standard operations procedu= re was to copy
>=C2=A0 > important tapes to new media periodically.
>
> There are always ways in which your backups can go wrong and not be > readable, and I'm not arguing that here.
>
> But 9 track tapes have turned out to be pretty spectacularly long-live= d.
> I've personally read tapes that were stored for 30+ years in
> unconditioned spaces.

Contrast that with the write only exabyte tapes.=C2=A0 I lost some stuff to= those.

There is a reason that exabyte no longer exists. It used to take up = a big swath of central Boulder.

Warner=C2=A0
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