From owner-freebsd-stable@freebsd.org Tue Aug 23 11:12:56 2016 Return-Path: Delivered-To: freebsd-stable@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id C1E60BC33C3 for ; Tue, 23 Aug 2016 11:12:56 +0000 (UTC) (envelope-from dim@FreeBSD.org) Received: from tensor.andric.com (tensor.andric.com [87.251.56.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "tensor.andric.com", Issuer "COMODO RSA Domain Validation Secure Server CA" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 8656B1E38 for ; Tue, 23 Aug 2016 11:12:56 +0000 (UTC) (envelope-from dim@FreeBSD.org) Received: from coleburn.avinity.tv (unknown [77.95.97.98]) (using TLSv1 with cipher ECDHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by tensor.andric.com (Postfix) with ESMTPSA id E9FE739C1A; Tue, 23 Aug 2016 13:12:47 +0200 (CEST) Subject: Re: Problems while reading from /dev/cd0 Mime-Version: 1.0 (Mac OS X Mail 9.3 \(3124\)) Content-Type: multipart/signed; boundary="Apple-Mail=_D0C014CB-281D-4F98-9F67-4C2984750635"; protocol="application/pgp-signature"; micalg=pgp-sha1 X-Pgp-Agent: GPGMail 2.6.1 From: Dimitry Andric In-Reply-To: Date: Tue, 23 Aug 2016 13:12:33 +0200 Cc: freebsd-stable Message-Id: <66E3F5E4-F640-4E05-A2CF-E7AD5F7D8327@FreeBSD.org> References: To: schmidt@ze.tum.de X-Mailer: Apple Mail (2.3124) X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.22 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 23 Aug 2016 11:12:56 -0000 --Apple-Mail=_D0C014CB-281D-4F98-9F67-4C2984750635 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=us-ascii On 23 Aug 2016, at 08:50, Gerhard Schmidt wrote: > > I'm having some very curios Problems while reading from an BD-R recorded > as a tar directly on the disk without a filesystem. > > When i try to read the Disk via 'tar tvvf /dev/cd0' > > i get the following output > > -rw-r--r-- 0 root wheel 5793264611 1 Jan 2015 file1.db > tar: Error reading '/dev/cd0' > Archive Format: POSIX ustar format, Compression: none > tar: Error exit delayed from previous errors. > > reading the whole file via 'dd if=/dev/cd0 of=backup.tar bs=2048' and > than 'tar tvvf backup.tar' the file is read without a hitch. So the data > on the disk is OK but can't be read directly by tar. > > if i try the dd without the bs=2048 i get > > dd: /dev/cd0: Invalid argument > 0+0 records in > 0+0 records out > 0 bytes transferred in 0.000115 secs (0 bytes/sec) > > So there is a problem reading anything other than 2048 byte blocks from > a Disk. Have you tried tar's -b option, to set the block size 2048? Maybe that will help. -Dimitry --Apple-Mail=_D0C014CB-281D-4F98-9F67-4C2984750635 Content-Transfer-Encoding: 7bit Content-Disposition: attachment; filename=signature.asc Content-Type: application/pgp-signature; name=signature.asc Content-Description: Message signed with OpenPGP using GPGMail -----BEGIN PGP SIGNATURE----- Version: GnuPG/MacGPG2 v2.0.30 iEYEARECAAYFAle8L64ACgkQsF6jCi4glqPJ3QCfQ4saDKcGJQa7xhwYqtabPpKm +zkAoKVT39WDHCSIXfiM2/1YCcLxDN8m =/fiC -----END PGP SIGNATURE----- --Apple-Mail=_D0C014CB-281D-4F98-9F67-4C2984750635--