media check fail

[Bob Parker]

Knute Johnson wrote:
> I've read several people say they did a SHA1SUM on the disks.  Is 
> that possible or did they actually do it to the ISO file?  If it is 
> possible, could some body tell me how to do it?
> 
> Thanks,
> 
> 

For what you have on the hard drive:
sha1sum something.iso

For what you have burnt:
a. mount the cdr
b. df
c, get the number of 1 k blocks on the cdrom device, divide that by 
2 to get the number of 2k sectors.
d. unmount the cdr
d. readcd dev=/dev/hdc f=- sectors=0-<number of 2k sectors> | sha1sum

To avoid read errors or incorrect sha1sum do not use readcd without 
specifying the sector count.

Substitute /dev/<your device> for /dev/hdc as required.

If you are using a dvd device to read your cdr you might get away with:
dd if=/dev/hdc bs=2048 count=<number of 2k sectors> | sha1sum
instead of readcd.


HTH
Bob