Verify a CD or DVD once it has been burned from an ISO file.
[With acknowlegements to http://www.troubleshooters.com/linux/coasterless.htm#_TestingCD ]and http://www.troubleshooters.com/linux/coasterless.htm#rawread ]
With the newly burned CD or DVD do the following : --
-
Put your CD or DVD into the drive and close the drive. This will normally mount the drive and pop up a window in Konqueror or other file browser which you can now close.
-
Find the device and mounted point of the Optical Medium.
You can find out the right path to your drive by doing : --
df -a
[root@localhost cdrom]# df -a
Filesystem Size Used Avail Use% Mounted on
/dev/root 117M 14M 103M 12% /
none 0 0 0 - /proc
none 0 0 0 - /dev/pts
none 0 0 0 - /proc/sys/fs/binfmt_misc
/dev/hdc 693M 693M 0 100% /mnt/cdrom
[root@localhost cdrom]#
or better,
df -a | grep cdrom
paul@paul-ArtistX07:~$ df -a | grep cdrom
/dev/sr0 953394 953394 0 100% /media/cdrom0
paul@paul-ArtistX07:~$
-
Find the correct information about how the CD or DVD is formatted.
Better method : You can get only the required information in the next step by adding '| grep size', so : --
isoinfo -d -i /dev/cdrom | grep size
paul@paul-ArtistX07:~$ isoinfo -d -i /dev/cdrom | grep size
Volume set size is: 1
Logical block size is: 2048
Volume size is: 476697
paul@paul-ArtistX07:~$
Saves time and effort in looking for this information!
Older, full-information method :
isoinfo -d -i /dev/cdrom [or whatever your device is called, sometime cdrom0, cdrom1 etc]
I am now working in PCLinuxOS [April 2007] and here is the output from a terminal window : --
Note :
I moved into this folder using the cd command, thus 'cd /dev/cdrom', to verify that the cd
was mounted at that point, and found the contents of the cd shown OK. Then ...
[root@localhost cdrom]# isoinfo -d -i /dev/cdrom
CD-ROM is in ISO 9660 format
System id: LINUX
Volume id: MDVCDROOT
Volume set id:
Publisher id:
Data preparer id:
Application id: MKISOFS ISO 9660/HFS FILESYSTEM BUILDER & CDRECORD CD-R/DVD CREATOR (C) 1993 E.YOUNGDALE (C) 1997 J.PEARSON/J.SCHILLING
Copyright File id:
Abstract File id:
Bibliographic File id:
Volume set size is: 1
Volume set sequence number is: 1
Logical block size is: 2048
Volume size is: 354816
El Torito VD version 1 found, boot catalog is in sector 45
Joliet with UCS level 3 found
Rock Ridge signatures version 1 found
Eltorito validation header:
Hid 1
Arch 0 (x86)
ID ''
Key 55 AA
Eltorito defaultboot header:
Bootid 88 (bootable)
Boot media 0 (No Emulation Boot)
Load segment 0
Sys type 0
Nsect 4
Bootoff 16C 364
[root@localhost cdrom]#
The essential information gleaned from this is block size 2048 and volume size 354816,
which translates to 726,663,168 bytes [693 MB]
-
Now use the 'dd' and the 'md5sum' commands to compute the md5sum from the CD or DVD.
Using this information in the command line to calculate the md5sum goes tike this : --
[root@localhost cdrom]# dd if=/dev/cdrom bs=2048 count=354816 conv=notrunc,noerror | md5sum
Translation :
Translated, this means dd = data dump [copy byte by byte, the required partiton, device or file].
if = Input file, specified as a device, with the file system specified.
| means that the output is piped to another application, in this case the md5sum app.
md5sum then computes the digest for the entire CD.
[root@localhost cdrom]# dd if=/dev/cdrom bs=2048 count=354816 conv=notrunc,noerror | md5sum
354816+0 records in
354816+0 records out
7f897c49f65232d6bddc5ee75148eae2 -
726663168 bytes (727 MB) copied, 196.553 seconds, 3.7 MB/s
[root@localhost cdrom]#
The published md5sum for this ISO is : --
7f897c49f65232d6bddc5ee75148eae2 mandriva-linux-2007-spring-one-KDE-cdrom-i586.iso so it checks out as OK.
Full output from the Konsole window : --
____________________________________________________________________________________________________
Complete Konsole output.
[root@localhost /]# df -a
Filesystem Size Used Avail Use% Mounted on
/dev/root 117M 12M 105M 11% /
none 0 0 0 - /proc
none 0 0 0 - /dev/pts
none 0 0 0 - /proc/sys/fs/binfmt_misc
/dev/hdc 693M 693M 0 100% /mnt/cdrom
[root@localhost /]# cd /mnt/cdrom
[root@localhost cdrom]# ls -l
total 95
dr-xr-xr-x 4 root root 2048 Apr 12 06:40 boot/
dr-xr-xr-x 2 root root 6144 Apr 12 06:40 isolinux/
-rw------- 1 root root 44719 Apr 12 06:40 LISEZMOI.pdf
dr-xr-xr-x 2 root root 2048 Apr 12 06:40 loopbacks/
-rw------- 1 root root 41584 Apr 12 06:40 README.pdf
[root@localhost cdrom]# isoinfo -d -i /mnt/cdrom
isoinfo: Is a directory. Read error on old image
[root@localhost cdrom]# isoinfo -d -i /dev/cdrom
CD-ROM is in ISO 9660 format
System id: LINUX
Volume id: MDVCDROOT
Volume set id:
Publisher id:
Data preparer id:
Application id: MKISOFS ISO 9660/HFS FILESYSTEM BUILDER & CDRECORD CD-R/DVD CREATOR (C) 1993 E.YOUNGDALE (C) 1997 J.PEARSON/J.SCHILLING
Copyright File id:
Abstract File id:
Bibliographic File id:
Volume set size is: 1
Volume set sequence number is: 1
Logical block size is: 2048
Volume size is: 354816
El Torito VD version 1 found, boot catalog is in sector 45
Joliet with UCS level 3 found
Rock Ridge signatures version 1 found
Eltorito validation header:
Hid 1
Arch 0 (x86)
ID ''
Key 55 AA
Eltorito defaultboot header:
Bootid 88 (bootable)
Boot media 0 (No Emulation Boot)
Load segment 0
Sys type 0
Nsect 4
Bootoff 16C 364
[root@localhost cdrom]# df -a
Filesystem Size Used Avail Use% Mounted on
/dev/root 117M 14M 103M 12% /
none 0 0 0 - /proc
none 0 0 0 - /dev/pts
none 0 0 0 - /proc/sys/fs/binfmt_misc
/dev/hdc 693M 693M 0 100% /mnt/cdrom
[root@localhost cdrom]# dd if=/dev/cdrom bs=2048 count=354816 conv=notrunc,noerror | md5sum
354816+0 records in
354816+0 records out
7f897c49f65232d6bddc5ee75148eae2 -
726663168 bytes (727 MB) copied, 196.553 seconds, 3.7 MB/s
[root@localhost cdrom]#
Comments (0)
You don't have permission to comment on this page.