[sunshine@MagicLinux tmp_iso]$ sudo mkisofs -V MagicLinux-2.5-1 -b boot/grub/grldr -c boot/grub/boot.cat -no-emul-boot -boot-load-size 4 -boot-info-table -J -T -r -f -o MagicLinux-2.5.1.iso magic_iso
Warning: -follow-links does not always work correctly; be careful.
I: -input-charset not specified, using gb18030 (detected in locale settings)
Size of boot image is 4 sectors -> No emulation
40.16% done, estimate finish Sat Jun 19 18:34:39 2010
80.15% done, estimate finish Sat Jun 19 18:34:39 2010
Total translation table size: 7601
Total rockridge attributes bytes: 2948
Total directory bytes: 7132
Path table size(bytes): 50
Max brk space used 1b000
12481 extents written (24 MB)
[sunshine@MagicLinux tmp_iso]$ ls
magic_iso MagicLinux-2.5.1.iso
This problem arises because mkisofs/genisoimage looks for its boot image as a subdirectory of the filesystem on the CD; make sure that the path you specify starts with 'boot/' rather than the name of your ISO directory ('isofiles/' in this example).