[opensuse] Burning dvd size mismatch.
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Hi, I burnt a dvd (non iso) using this command line: growisofs -Z /dev/hdc=image Then, I compared the result: cmp /dev/hdc image and got this: cmp: EOF on /Grande/imgs/image Thus, to check whether everything was saved, I extracted the image from the dvd: nimrodel:/Grande/imgs # dd if=/dev/hdc of=dvd 9179712+0 records in 9179712+0 records out 4700012544 bytes (4.7 GB) copied, 392.888 s, 12.0 MB/s and compared the sizes: 4700000000 image 4700012544 dvd Ie, the dvd image extracted from the dvd is slightly bigger. I assume this must be some kind of end of track adjustment, but it means that the compare fails. I think I can compare doing this instead: nimrodel:/Grande/imgs # cmp --bytes=4700000000 image /dev/hdc and they match. I can extract the extra bytes: nimrodel:/Grande/imgs # dd if=dvd of=extra skip=4700 ibs=1MB 0+1 records in 24+1 records out 12544 bytes (13 kB) copied, 0.0236522 s, 530 kB/s and it is all zeroes. Am I correct, is this to be expected, or am I doing something wrong? - -- Cheers, Carlos Robinson -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.5 (GNU/Linux) Comment: Made with pgp4pine 1.76 iD8DBQFGQdT6tTMYHG2NR9URAniEAJ4p+nDT0aQuX9EHKLqgsBXv3mEpYwCcD61h 8qCK4GqtCXNlgNimCh6QHEw= =jX3g -----END PGP SIGNATURE----- -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Carlos E. R. wrote:
Hi,
I burnt a dvd (non iso) using this command line:
growisofs -Z /dev/hdc=image
Then, I compared the result:
cmp /dev/hdc image
and got this:
cmp: EOF on /Grande/imgs/image
Thus, to check whether everything was saved, I extracted the image from the dvd:
nimrodel:/Grande/imgs # dd if=/dev/hdc of=dvd 9179712+0 records in 9179712+0 records out 4700012544 bytes (4.7 GB) copied, 392.888 s, 12.0 MB/s
and compared the sizes:
4700000000 image 4700012544 dvd
Ie, the dvd image extracted from the dvd is slightly bigger. I assume this must be some kind of end of track adjustment, but it means that the compare fails.
I think I can compare doing this instead:
nimrodel:/Grande/imgs # cmp --bytes=4700000000 image /dev/hdc
and they match.
I can extract the extra bytes:
nimrodel:/Grande/imgs # dd if=dvd of=extra skip=4700 ibs=1MB 0+1 records in 24+1 records out 12544 bytes (13 kB) copied, 0.0236522 s, 530 kB/s
and it is all zeroes.
Am I correct, is this to be expected, or am I doing something wrong?
I have found after using a star archive burned on DVD with the above via growisofs that when I eventually got the the archive back it had copied everything to the end of media, a 2.7G file became 4.7G (not a result I wanted :-( ) [star had some peculiar issues with compression which made the archive unusable from dvd]. BTW According to the man pages growisofs/wodim always creates an iso structure to write data into (at least on DVD+RW media, as DVD- media are more geared towards multi-media streams they are not good for random data access and these are not pre-formatted, which is understandable for RO media but a possible issue with DVD-RW ), in the above case you have a binary image placed on an iso low level format if on DVD+RW. What you can do with it afterwards seems to be rather dependant on media and device capabilities, the best way you can look at it is that it seems to act as a buffered stream when writing, and an unbuffered data stream when reading. Unfortunately any relevant end of stream markers seem to be ignored when reading (if any exist ). -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.5 (GNU/Linux) Comment: Using GnuPG with SUSE - http://enigmail.mozdev.org iD8DBQFGQhx0asN0sSnLmgIRAnefAKCePpae+GSCzyjl73alx26Y6D2E+wCgqNI2 vmOlbB6sIB6rLxont+tSjqg= =kiq1 -----END PGP SIGNATURE----- -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org
Thus, to check whether everything was saved, I extracted the image from the dvd:
nimrodel:/Grande/imgs # dd if=/dev/hdc of=dvd 9179712+0 records in 9179712+0 records out 4700012544 bytes (4.7 GB) copied, 392.888 s, 12.0 MB/s
and compared the sizes:
4700000000 image 4700012544 dvd
# expr \( 4700000000 + 16383 \) / 16384 \* 16384 4700012544 Apparently, while being written, the image is expanded to the next multiple of 16k (might be even 32k or 64k). A single block on DVDs is 2048 bytes, I don't remember how big a group is (data needs to be written in groups due to error correction codes). HTH Matthias -- Matthias Hopf <mhopf@suse.de> __ __ __ Maxfeldstr. 5 / 90409 Nuernberg (_ | | (_ |__ mat@mshopf.de Phone +49-911-74053-715 __) |_| __) |__ R & D www.mshopf.de -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 The Tuesday 2007-05-15 at 17:40 +0200, Matthias Hopf wrote:
and compared the sizes:
4700000000 image 4700012544 dvd
# expr \( 4700000000 + 16383 \) / 16384 \* 16384 4700012544
Apparently, while being written, the image is expanded to the next multiple of 16k (might be even 32k or 64k). A single block on DVDs is 2048 bytes, I don't remember how big a group is (data needs to be written in groups due to error correction codes).
I was thinking of something in that line, though I wonder why I hadn't noticed before. I don't know how many blocks have to be written at a time either. - -- Cheers, Carlos E. R. -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.5 (GNU/Linux) Comment: Made with pgp4pine 1.76 iD8DBQFGTCmAtTMYHG2NR9URAhzeAKCQXwjpcFvcYGJN/nWkX4YRg9uoTACeNKSa I79Od5jE9qin87dUg4Hc564= =Q3dj -----END PGP SIGNATURE----- -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org
participants (3)
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Carlos E. R. -
G T Smith -
Matthias Hopf