On 23 May 2010, at 15:31, Manolis Kiagias wrote: > On 24/05/2010 1:23 π.μ., Doug Hardie wrote: >> I am periodically backing up a bunch of files to DVD. I use mkisofs to >> create the original image and growisofs to write it to a real DVD. However, >> at that point I want to verify that the write was successful. I tried using >> dd to read back in the DVD to a file. Its interesting that the bs parameter >> must be at least 2048 or dd complains about a parameter error. However, the >> big issues is that the original image file is shorter than the read file. >> The difference is 10240 bytes. This difference is the same for bs 2048, >> 10240, or 102400. It appears that dd is adding one last block. Is there a >> way to prevent this or remove that block? >> > > Use the count= parameter in dd to read the exact count of blocks in the > DVD. Use isoinfo to obtain this information from the media itself. Have > a look at the instructions here: > > http://www.troubleshooters.com/linux/coasterless.htm > >
Thanks. That works great. I did discover that appending 10240 zeros to the end of the original iso file also works. However, I am not convinced that it will always be that value. The approach above should be more reliable._______________________________________________ firstname.lastname@example.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "freebsd-questions-unsubscr...@freebsd.org"