Date: Tue, 23 Aug 2016 13:12:33 +0200 From: Dimitry Andric <dim@FreeBSD.org> To: schmidt@ze.tum.de Cc: freebsd-stable <freebsd-stable@freebsd.org> Subject: Re: Problems while reading from /dev/cd0 Message-ID: <66E3F5E4-F640-4E05-A2CF-E7AD5F7D8327@FreeBSD.org> In-Reply-To: <ba79f0d6-a9e5-623c-d1b7-fb188202befb@ze.tum.de> References: <ba79f0d6-a9e5-623c-d1b7-fb188202befb@ze.tum.de>
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--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 <estartu@ze.tum.de> 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--
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