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, MAILING_LIST_MULTI,RCVD_IN_DNSWL_NONE autolearn=ham autolearn_force=no version=3.4.4 Received: (qmail 1499 invoked from network); 24 Feb 2021 02:23:45 -0000 Received: from minnie.tuhs.org (45.79.103.53) by inbox.vuxu.org with ESMTPUTF8; 24 Feb 2021 02:23:45 -0000 Received: by minnie.tuhs.org (Postfix, from userid 112) id 785BB9C852; Wed, 24 Feb 2021 12:23:42 +1000 (AEST) Received: from minnie.tuhs.org (localhost [127.0.0.1]) by minnie.tuhs.org (Postfix) with ESMTP id E76529C6D0; Wed, 24 Feb 2021 12:23:08 +1000 (AEST) Authentication-Results: minnie.tuhs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=utah.edu header.i=@utah.edu header.b="QHOk3Pxq"; dkim-atps=neutral Received: by minnie.tuhs.org (Postfix, from userid 112) id 976579C6D0; Wed, 24 Feb 2021 12:23:05 +1000 (AEST) Received: from ipo12.cc.utah.edu (ipo12.cc.utah.edu [155.97.144.22]) by minnie.tuhs.org (Postfix) with ESMTPS id 82B5F9C6CE for ; Wed, 24 Feb 2021 12:23:02 +1000 (AEST) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=utah.edu; i=@utah.edu; q=dns/txt; s=UniversityOfUtah; t=1614133382; x=1645669382; h=date:from:to:cc:subject:in-reply-to:message-id; bh=el+uswqeRJDrVuPMDePQpHKOHqd4Nb/pBZ6+XtIJDSw=; b=QHOk3Pxqhic4cMZgrqXqwPXJuVaZ4IIMWlWXnPObT/zVuCaZOdQaEYem oYrGNaKw3v6pADzskUUP+amEYRiSDU19NkplTSQsj67UIc7229165in4o zBgWeOUoSxPET9g3fCgL7CG8PBVg1UCy3ZmQMZMwiICvE6yVGjwvMnX5I C7YTh6aStIKE19PIbqPw+FRxWsACe0Ks7DJYUu2wsTjidjm25by3vEjDH 8bt1X8eGXM4tcOJodY/W6EWwyWSn6SZ8y8raAw6epCtdj6nrKajB5z5GZ uj3JPCNCFIq1aB6abwchlSjeVtK+tbyX22+QmbgOBUIW9CvTBlBnJU1Vx g==; IronPort-SDR: LJ1MZ76U1JjGf5QUcQeBjCTxF2KzWwDIMGgCtdBsy9RNYWgS+njWKAgXZUUdUR2rW8fctUqzoS VAhz+yobVHS9vUuRHFvwJV+tVd9d5N433opCk6E6ph61JAxRdpVbc6LXl2OAjBxl4hPJ9DLIiD YqaWAdYTYn6JZDIwRvfnJkkappJNPlWV+6S0fFfNI/B/A1+UEVm2nrFOgzSui3C4zVHuwgem7P 7qmoKLPMS///9MfqQfqw0QdFZNKrLByYQyl3ywZhvNGJUynGH0cglPMEbmSYXeTPQ6tI866BYO xJk= X-IronPort-AV: E=Sophos;i="5.81,201,1610434800"; d="scan'208";a="94473114" Received: from mail.math.utah.edu ([155.101.98.135]) by ipo12smtp.cc.utah.edu with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 23 Feb 2021 19:23:02 -0700 Received: from gamma.math.utah.edu (gamma.math.utah.edu [155.101.96.20]) by mail.math.utah.edu (8.16.1/8.16.1) with ESMTP id 11O2N16L001255; Tue, 23 Feb 2021 19:23:01 -0700 (MST) Received: from gamma.math.utah.edu (localhost [127.0.0.1]) by gamma.math.utah.edu (8.15.1/8.15.1) with ESMTP id 11O2N1N9029588; Tue, 23 Feb 2021 19:23:01 -0700 Received: (from beebe@localhost) by gamma.math.utah.edu (8.15.1/8.15.1/Submit) id 11O2N1ZI029587; Tue, 23 Feb 2021 19:23:01 -0700 Date: Tue, 23 Feb 2021 19:23:01 -0700 From: "Nelson H. F. Beebe" To: The Unix Heritage Society mailing list X-US-Mail: "Department of Mathematics, 110 LCB, University of Utah, 155 S 1400 E RM 233, Salt Lake City, UT 84112-0090, USA" X-Telephone: +1 801 581 5254 X-FAX: +1 801 581 4148 X-URL: http://www.math.utah.edu/~beebe In-Reply-To: Message-ID: X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.3.8 (mail.math.utah.edu [155.101.98.135]); Tue, 23 Feb 2021 19:23:01 -0700 (MST) Subject: Re: [TUHS] Abstractions 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: , Errors-To: tuhs-bounces@minnie.tuhs.org Sender: "TUHS" Greg Woods responds to my posting: >> Hmmmm... you may just be mixing up the names of the archive tools you >> mean, but on the other hand maybe you don't know that "dump" does whole >> filesystems, not just sub-directories. I meant "dump" as a generic verb, not specifically the Unix dump utility. Many sites also used tar to backup directory trees: after all, tar means Tape ARchiver. >> Original Unix dump(1m) had no trouble asking for additional tapes ... That was, however, contingent on a reliable signal from the tape unit, and my strong recollection is that when we moved to various types of cheap cassette tapes, the end-of-tape indicator was unreliable. Thus, we paid attention to both disk and tape sizes. Today, with 10TB+ on LTO-8 tapes, it isn't an issue for us, and we also tend to have many different ZFS volumes representing various parts of the filesystem, allowing different backup and snapshotting policies. Besides tapes and snapshots, we also have a live SAN mirror, and a remote snapshot server, giving plenty of data replication, and the warm fuzzy feelings from that. After 20 years of ZFS, I don't recall us ever losing data. We have also gone through two generations of major fileserver upgrades and complete data migrations without service interruptions (except for a brief interval for each user account to synchronize data on old and new servers). ------------------------------------------------------------------------------- - Nelson H. F. Beebe Tel: +1 801 581 5254 - - University of Utah FAX: +1 801 581 4148 - - Department of Mathematics, 110 LCB Internet e-mail: beebe@math.utah.edu - - 155 S 1400 E RM 233 beebe@acm.org beebe@computer.org - - Salt Lake City, UT 84112-0090, USA URL: http://www.math.utah.edu/~beebe/ - -------------------------------------------------------------------------------