kmack Posted April 9, 2003 Report Share Posted April 9, 2003 I was having trouble figuring out how to do md5sum on new CD's I ordered for ML 9.1. I could not get the md5sum to verify my CD's. I searched this list, read man:md5sum, and thought I understood the process, but no joy. The checksums were off! I hate to get beat by a machine! So, I kept reading and trying. Victory! When I finally learned the correct syntax my CD's were verified! Maybe my post will help someone else avoid this mistake. [kelly@localhost kelly]$ mount /mnt/scd1 mount: block device /dev/scd1 is write-protected, mounting read-only [kelly@localhost kelly]$ cat /dev/scd1 | md5sum 6f1581974e12420fef87868ed6caa31f - [kelly@localhost kelly]$ eject /dev/scd1 [kelly@localhost kelly]$ mount /mnt/scd1 mount: block device /dev/scd1 is write-protected, mounting read-only [kelly@localhost kelly]$ cat /dev/scd1 | md5sum 87afe11ddef6b619866322aa0797e45f - [kelly@localhost kelly]$ eject /mnt/scd1 [kelly@localhost kelly]$ mount /mnt/scd1 mount: block device /dev/scd1 is write-protected, mounting read-only [kelly@localhost kelly]$ cat /dev/scd1 | md5sum ff187c7a552722f42790b5726fdb62b3 - Earlier I tried doing md5sum with the cmd $cat /mnt/scd1 | md5sum because I thought I needed to substitute the /dev/scd1 with the /mnt/scd1 WRONG! It won't work properly. I also tried making an iso of the CD's and doing checksum of each new iso and was wrong as I still used the wrong syntax. Lesson learned! There is probably a more elegant way to do this, but this worked for me and I am learning as I go. I disabled supermount btw, that is why I am mounting the device manually. I am not clear why /mnt/scd1 won't work and /dev/scd1 does work but I will keep digging to figure this out. (If you try this at home, you must substitute your own cdrom names here btw) Anyhow, thanks to previous posters and replies that pointed me in the right direction. "If at first you don't succeed, try, try again!" :D Quote Link to comment Share on other sites More sharing options...
tyme Posted April 9, 2003 Report Share Posted April 9, 2003 I think the difference between /mnt/scd1 and /dev/scd1 is that /mnt/scd1 is just the directory in which the cd-rom gets mounted, so that you can access the files. Meanwhile, /dev/scd1 is the actual device, not just it's files. Quote Link to comment Share on other sites More sharing options...
kmack Posted April 9, 2003 Author Report Share Posted April 9, 2003 tyme, Thanks! Yes, that is my understanding so far. I was totally convinced that I understood the syntax and blindly exchanged them to get wrong results. DUH... guess it is part of learning. Appreciate your assistance and insight. It really helps me figure this out. :lol: Quote Link to comment Share on other sites More sharing options...
tyme Posted April 9, 2003 Report Share Posted April 9, 2003 Appreciate your assistance and insight. It really helps me figure this out. :lol: hey, that's what we're here for, right? :D Quote Link to comment Share on other sites More sharing options...
pmpatrick Posted April 9, 2003 Report Share Posted April 9, 2003 Here's a link you might be interested in: http://www.troubleshooters.com/linux/coasterless.htm It's a very good article dealing with problems with cd burning but gets into a discusion of md5sums of cds. The article includes a bash script which will eliminate the possibility of read errors affecting the md5sum calculation. It's a little more thorough than your method, perhaps overkill, but I've used it for some time with excellent results. Quote Link to comment Share on other sites More sharing options...
kmack Posted April 9, 2003 Author Report Share Posted April 9, 2003 pmpatrick: Great resource Thanks! I will make it a learning experience, digest this and give it a try as it does appear more thorough. Linux sure has lots of ways to do things! Power to the users! :wink: Quote Link to comment Share on other sites More sharing options...
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