1Mini-Howto for verifying a selfmade CD 2 31) verifying the data layer 4 5 To verify if all data on the disk can be read, 6 use SCSI verify. This can be done with the 7 sformat utility. 8 9 use: sformat -verify [target] [lun] [scsibus] 10 11 If the CD-R device is connected to target 2 on SCSI bus 0 12 sformat -verify 2 0 13 14 sformat can be found on ftp://ftp.berlios.de/pub/sformat 15 16 NOTE: Not all CD-ROm drives support verifying 17 NOTE: All TAO tracks end in 2 unreadable run-out sectors 18 192) verifying the filesystem layer 20 21 A quick check is to mount the CD and to use star to read 22 all files on the filesystem. 23 24 mount -r /dev/cdrom /cdrom (modify for your OS) 25 cd /cdrom 26 star -cPM . >/dev/null 27 28 If no errors can be found, all files are readable. 29 30 star can be found on ftp://ftp.berlios.de/pub/star 31 32 33 You also may want to compare the filesystem on the CD 34 with the original data. This can be done with star too. 35 36 37 (cd /master_for_cd; star -cPM .)|(cd /cdrom; star -diff -v) 38 392a) verifying the iso image before creating the CD 40 41 You may check the filesystem image by mounting it with my 42 "fbk" on Solaris or the loopback driver on Linux. 43 44 On Linux type: 45 mount isoimage.raw -r -t iso9660 -o loop /mnt 46 47 On SunOS type: 48 mount -r -F fbk -o type=hsfs /dev/fbk0:isoimage.raw /mnt 49 50For Solaris 8 and later you may also use the Sun lofi driver (see README.sun-lofi) 51 52 The check the filesystem with: 53 54 (cd /master_for_cd; star -cPM .)|(cd /mnt; star -diff -v) 55 56 57Solaris has a bug with hardlinks. It generates different inode numbers 58for the hardlinks to a file. This makes it impossible for star to 59check hard links. Use 60 61(cd /master_for_cd; star -cPM .)|(cd /cdrom; star -diff -v diffopts=!hardlink) 62 63in this case. 64 65NOTE: Some operating systems have a read ahead bug that causes I/O errors for 66the last file(s) on a CD. This seems at least to be true for all Linux versions 67and for Solaris 7 FCS. For Solaris 7 there is a patch (107465-02) that you should 68install. This I/O error problem does not occur with DAO disks and with TAO disks 69that have been written with wodim -pad. 70 71Joerg Schilling 72 73Source: README.verify from cdrtools package 74Edited for cdrkit by Christian Fromme <kaner@strace.org> and Eduard Bloch 75 76