From owner-freebsd-current Mon Aug 26 13:15:55 1996 Return-Path: owner-current Received: (from root@localhost) by freefall.freebsd.org (8.7.5/8.7.3) id NAA12662 for current-outgoing; Mon, 26 Aug 1996 13:15:55 -0700 (PDT) Received: from vector.jhs.no_domain (slip139-92-42-175.ut.nl.ibm.net [139.92.42.175]) by freefall.freebsd.org (8.7.5/8.7.3) with ESMTP id NAA12649; Mon, 26 Aug 1996 13:15:45 -0700 (PDT) Received: from vector.jhs.no_domain (localhost [127.0.0.1]) by vector.jhs.no_domain (8.7.5/8.6.9) with ESMTP id RAA16960; Mon, 26 Aug 1996 17:17:42 +0200 (MET DST) Message-Id: <199608261517.RAA16960@vector.jhs.no_domain> To: Bora Akyol cc: joerg_wunsch@uriah.heep.sax.de, freebsd-current@freebsd.org (FreeBSD-current users), hoek@freenet.hamilton.on.ca Subject: Re: Help on block size in tar From: "Julian H. Stacey" Reply-To: "Julian H. Stacey" Organization: Vector Systems Ltd. Address: Holz Strasse 27d, 80469 Munich, Germany Phone: +49.89.268616 Fax: +49.89.2608126 Web: http://www.freebsd.org/~jhs/ Mailer: EXMH 1.6.7, PGP available In-reply-to: Your message of "Sat, 24 Aug 1996 10:06:40 EDT." <199608241406.KAA03455@james.freenet.hamilton.on.ca> Date: Mon, 26 Aug 1996 17:17:42 +0200 Sender: owner-current@freebsd.org X-Loop: FreeBSD.org Precedence: bulk Hi, Reference: > From: hoek@freenet.hamilton.on.ca > Subject: Re: Help on block size in tar > Date: Sat, 24 Aug 1996 10:06:40 -0400 (EDT) > Message-id: <199608241406.KAA03455@james.freenet.hamilton.on.ca> > > In Email, J Wunsch wrote: > > > > What is the default blocksize of tar on FreeBSD, I have made a tape > > > > on a freebsd system and now cannot read it on a linux system. > > > > > it may be more complicated... > > > it might be teh TAPE DRIVE complaining... > > > > Anyway, i think the default blocksize is only 512 bytes. This should > > also pass any variable-length driver. > > Are you sure? I quote the tar manpage (which, being GNU tar isn't the > official source of information regarding tar, I suppose). tar --help says: -b, --block-size N block size of Nx512 bytes (default N=20) so it is official. > "and 20 is the default block size" > > And each of these blocks are then 512 bytes, I believe. > > Or the manpage is just confusing the heck out of me. Maybe the tape drive used for writing was capable of variable blocking (like my "TANDBERG TDC 3800 =04Y" type 1 removable SCSI 2 Sequential-Access density code 0x0, drive empty ) If one writes a tape on that without `mt blocksize 512', and then tries to read it elsewhere, problems can occur.... so maybe the tape was written with variable blocking. Julian -- Julian H. Stacey jhs@freebsd.org http://www.freebsd.org/~jhs/