"M. Fioretti" wrote: > > On Sun, Apr 06, 2003 07:26:44 at 07:26:44AM +0200, io (m.fioretti@xxxxxxxxx) wrote: > > > > [root@xxxxxxx root]# cat /dev/cdrom | md5sum > > cat: /dev/cdrom: Input/output error > > but a checksum was indeed output > > > This method (at least on my computer and/or with the CDs I'm testing > it with) is unreliable/meaningless: it gives different checksums on > the same disc, depending on the PC load: why? This has something to do with the way the filesystem driver does read the CD contents - it doesn't necessarily stop exactly at the end of the data, especially if the CD was not burned in DAO mode (sorry, I'm no expert). I remember this discussion from several RHL lists in the past, IIRC the fix is to dd bs=2048 (or whatever blocksize the ISO filesystem was built with) instead of cat. Same goes for extracting the ISO filesystem. I think you shouldn't mount the CD for that, but try what works best... Best regards, Martin Stricker -- Homepage: http://www.martin-stricker.de/ Linux Migration Project: http://www.linux-migration.org/ Red Hat Linux 7.3 for low memory: http://www.rule-project.org/ Registered Linux user #210635: http://counter.li.org/
