-----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: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
