Checking MD5SUM from CDROM copy

Paul W. Frields paul at frields.com
Wed Oct 8 13:28:01 UTC 2003


On Wed, 2003-10-08 at 06:43, Ossama Khayaat wrote:
> > Hi,
> > I searched the archives for an article about verifying a copied .iso
> > image.
> > I found what I need but the problem is that when I issue the
> command, as
> > follows, what is the number specified after count= ?
> > [SNIP from thread: How to check *CDROM* correctness?]
> > [http://www.redhat.com/archives/shrike-list/2003-April/msg00637.html]
> > # dd if=/dev/cdrom bs=2048 count=326656 | md5sum
> > 1+0 records in
> > 1+0 records out
> > c99a74c555371a433d121f551d6c6398  -
> 
> Sorry, I checked the man page and it's number of blocks, which you can
> get if you use:
> # du /mnt/cdrom -s

Ossama,

If you have an MD5 sum for the whole CD, you can simply "md5sum
/dev/cdrom" and the disk will be read from first sector to the last one
written. If it's a Red Hat Linux or Fedora Core install CD, if you have
the anaconda-runtime RPM installed, you can simply do:

  /usr/lib/anaconda-runtime/checkisomd5 /dev/cdrom

Note that the most appropriate usage is to run against the device, and
not to mount the CD for these purposes, although mounting should not
affect the results on CD's.
-- 
Paul W. Frields, RHCE





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