Mini-Howto for verifying a selfmade CD 1) verifying the data layer To verify if all data on the disk can be read, use SCSI verify. This can be done with the sformat utility. use: sformat -verify [target] [lun] [scsibus] If the CD-R device is connected to target 2 on SCSI bus 0 sformat -verify 2 0 sformat can be found on ftp://ftp.berlios.de/pub/sformat NOTE: Not all CD-ROm drives support verifying NOTE: All TAO tracks end in 2 unreadable run-out sectors 2) verifying the filesystem layer A quick check is to mount the CD and to use star to read all files on the filesystem. mount -r /dev/cdrom /cdrom (modify for your OS) cd /cdrom star -cPM . >/dev/null If no errors can be found, all files are readable. star can be found on ftp://ftp.berlios.de/pub/star You also may want to compare the filesystem on the CD with the original data. This can be done with star too. (cd /master_for_cd; star -cPM .)|(cd /cdrom; star -diff -v) 2a) verifying the iso image before creating the CD You may check the filesystem image by mounting it with my "fbk" on Solaris or the loopback driver on Linux. On Linux type: mount isoimage.raw -r -t iso9660 -o loop /mnt On SunOS type: mount -r -F fbk -o type=hsfs /dev/fbk0:isoimage.raw /mnt For Solaris 8 and later you may also use the Sun lofi driver (see README.sun-lofi) The check the filesystem with: (cd /master_for_cd; star -cPM .)|(cd /mnt; star -diff -v) When doing this you have to know about the bugs in Linux/Solaris Mkisofs before 1.10 and Linux have a bug with timezones. If you are using mkisofs-1.10 and newer on Linux, you need to disable comparing times: (cd /master_for_cd; star -cPM .)|(cd /cdrom; star -diff -v diffopts=!times) The same is needed if you are using mkisofs pre-1.10 on Solaris Solaris has a bug with hardlinks. It generates different inode numbers for the hardlinks to a file. This makes it impossible for star to check hard links. Use (cd /master_for_cd; star -cPM .)|(cd /cdrom; star -diff -v diffopts=!hardlink) in this case. NOTE: Some operating systems have a read ahead bug that causes I/O errors for the last file(s) on a CD. This seems at least to be true for all Linux versions and for Solaris 7 FCS. For Solaris 7 there is a patch (107465-02) that you should install. This I/O error problem does not occur with DAO disks and with TAO disks that have been written with cdrecord -pad. Joerg Schilling