From owner-freebsd-questions@freebsd.org Sun Apr 29 08:54:19 2018 Return-Path: Delivered-To: freebsd-questions@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id AF673FA6D60 for ; Sun, 29 Apr 2018 08:54:19 +0000 (UTC) (envelope-from freebsd@edvax.de) Received: from mout.kundenserver.de (mout.kundenserver.de [212.227.126.130]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client CN "mout.kundenserver.de", Issuer "TeleSec ServerPass DE-2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id F423F79809 for ; Sun, 29 Apr 2018 08:54:18 +0000 (UTC) (envelope-from freebsd@edvax.de) Received: from r56.edvax.de ([92.195.45.149]) by mrelayeu.kundenserver.de (mreue005 [212.227.15.167]) with ESMTPA (Nemesis) id 0Ls5Ln-1eESEO0JyR-013sSt; Sun, 29 Apr 2018 10:54:11 +0200 Date: Sun, 29 Apr 2018 10:54:09 +0200 From: Polytropon To: Olivier Cc: "Frank Leonhardt \(m\)" , freebsd-questions@freebsd.org Subject: Re: Backing up to tape Message-Id: <20180429105409.d0e4b24c.freebsd@edvax.de> In-Reply-To: References: <28BACDED-FDCC-415B-AABA-732FE36A3E91@fjl.co.uk> Reply-To: Polytropon Organization: EDVAX X-Mailer: Sylpheed 3.1.1 (GTK+ 2.24.5; i386-portbld-freebsd8.2) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Provags-ID: V03:K1:AdW8AXkWlnqfcM8CGA8Apd1lEJtpaC1uAjvuvMSRtLyKikouEcO qFyHXSKZ6vyese4sJHrwlW2YQOgzB2LTGpEM7ed6munJxCdG1LLwNHxLDHraCn5n5JB5TkC RXvUF+ikn6EwxAio0ML1yZ6Rgf7iKiS0fUw78gZ12ADdDGucvLWangBjD9SKDuG970H7fU8 AQyosXqNLTrXpfWdnJKoQ== X-UI-Out-Filterresults: notjunk:1;V01:K0:p+FT4F1Ka40=:k+RJCSHahZta2uuP1GLqqD pPBu8exDtiamCexk3E+SEefPnfraUooNo9+SR372rwWSYYYbIM+ZvX6NW7KNzqH5gQnRR7n9+ Wijh8GtAOz5k2ycYy+TIEDTNCJv54SMRNEUtK+s69IKjk3QsOwGKBBdMBXwerbqL3rWVrIdzy NmHmh7gAM10JAmbDALvcgcWUr7z9bTcFBkb6peOPBx2hB63uEyLCzt9wEHrAxQMc12olizXtl LjnQoz+jqDRSEW8Z06yhsfQ/5FcCOhe6PdV5yRn5OWTDftVjUw9rhmRQskn8PIM5KBTN9NLTq xWkAIT1fr/VHOjaEUSIxdk6KbeD8gmhFufT8MQzHg5NpKlA2UJIGX/J8akYzIZetUrpZXj+fO Qm3C6urG2/9M22c4qRwjWRuiliy89OzsTx7sPofvam2oo2NjA/4Un9JoX2VFEzHwqULO4GElW LSjGS4eVk1pojt+LCSYkNodg2WVZrw5Yom5H4xNnV2XrDwx/OjC9sokvknZDWDIZGoKA6zW56 kpYtA5YI7BJYRJc8UQACrnLQtYkWVsiEho2kXzxWvYUKqfesnSlQci5VeSDzMSx5uH023jHYy uL5HQkA4+vR7eAbDC/t9MmzSGEicYw4zDhVAVAggttaegG49pBwcVVRXm+nkP1lp8inZL47KL Byt13ZMm9ZNiGp3iGi0YxuSgl13lPutOxz0cALNSZJUwJ2kj/Bbz10ie2SWZevN9aL1gVajm2 gYFv6FgzK0lsUbpG X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.25 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 29 Apr 2018 08:54:19 -0000 On Thu, 26 Apr 2018 17:32:28 +0700, Olivier wrote: > "Frank Leonhardt (m)" writes: > > I'll need a utility to save/restore ZFS datasets that are larger > > than one tape if anyone knows of one. Otherwise I'll be writing > > one, if anyone is interested. > > While it should not be too difficult to design such a utility, you have > to consider that each time you will want to access any data on the tar, > you will have to stream through all the tapes, because tar format does > not allow you to start with the tape 5 even if you know that the file > you are looking for is not on the first 4 tapes. In this case, pax is a convenient tool to deal with multi-volume archives. It is part of the default OS installation, of course. See "man pax" for details. > It would be much better to split the data you want to tar, to have one > set of data filling almost one tape. Splitting the data beforehand probably is the best way to deal with tar archives on tape. Maintaing a "tape catalog" (usually automated) is a nice addition. -- Polytropon Magdeburg, Germany Happy FreeBSD user since 4.0 Andra moi ennepe, Mousa, ...