From owner-freebsd-stable Thu Sep 3 21:16:58 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id VAA21335 for freebsd-stable-outgoing; Thu, 3 Sep 1998 21:16:58 -0700 (PDT) (envelope-from owner-freebsd-stable@FreeBSD.ORG) Received: from mail.HiWAAY.net (fly.HiWAAY.net [208.147.154.56]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id VAA21326 for ; Thu, 3 Sep 1998 21:16:56 -0700 (PDT) (envelope-from dkelly@n4hhe.ampr.org) Received: from nospam.hiwaay.net (tnt3-100.HiWAAY.net [208.147.146.100]) by mail.HiWAAY.net (8.9.0/8.9.0) with ESMTP id XAA14334; Thu, 3 Sep 1998 23:15:48 -0500 (CDT) Received: from n4hhe.ampr.org (localhost.ampr.org [127.0.0.1]) by nospam.hiwaay.net (8.8.8/8.8.8) with ESMTP id VAA17656; Thu, 3 Sep 1998 21:57:36 -0500 (CDT) (envelope-from dkelly@n4hhe.ampr.org) Message-Id: <199809040257.VAA17656@nospam.hiwaay.net> X-Mailer: exmh version 2.0.2 2/24/98 To: Frank Terhaar-Yonkers cc: freebsd-stable@FreeBSD.ORG From: David Kelly Subject: Re: 8mm tape block size max - changed? In-reply-to: Message from Frank Terhaar-Yonkers of "Wed, 02 Sep 1998 21:19:42 EDT." <199809030119.VAA25476@claret.cisco.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Date: Thu, 03 Sep 1998 21:57:35 -0500 Sender: owner-freebsd-stable@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG Frank Terhaar-Yonkers writes: > > Folks - > > I recently upgraded from 2.0.x where I routinely used a block size of > 128b with tar and dump. Using 2.1.7 I get: st0: 64512-byte record too big > when I try to read the old tapes. > > Now I have all these old tapes I can't read. Am I missing something? So you used "tar -cvb 128 files" to write a tar tape? Would suggest you try using tcopy to determine what blocksize is being used but I just tried it myself and it didn't work right at all. Multiple tape blocks were read to serve one read(). If this is happening to you then that may be the key to the puzzle: The following tape was written "tar -cvb 20", tcopy clearly reports an incorrect block size and would mangle this tape if I were to actually copy it: n4hhe: {541} tcopy file 0: block size 65536: records 0 to 7 file 0: block size 43008: record 7 file 0: eof after 8 records: 501760 bytes eot total length: 501760 bytes n4hhe: {542} The above is *not* the way I'm used to seeing tcopy work. Am dissapointed. Recently ported FreeBSD's tcopy to SGI Irix 6.3 and had the same problem if a non-variable blocksize device was used (ie: /dev/rmt/tps1d6nrv worked, /dev/rmt/tps1d6nr would supply multiple blocks to fill the read() request). So maybe I'm just using the wrong FreeBSD tape device? dmesg says: (ahc0:6:0): "ARCHIVE ANCDA 2750 28077 -003" type 1 removable SCSI 2 st0(ahc0:6:0): Sequential-Access density code 0x10, 512-byte blocks, write-enabled To my knowlege FreeBSD has never been able to write blocks larger than 64k to tape devices but would hide large writes with multiple smaller writes. So with any luck if you were writing 128 * 512 bytes then you should be OK. THe 64512 number you quote has everyone confused. -- David Kelly N4HHE, dkelly@nospam.hiwaay.net ===================================================================== The human mind ordinarily operates at only ten percent of its capacity -- the rest is overhead for the operating system. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-stable" in the body of the message