menuentry "Damn Small Linux (on /dev/sdb8)" --class gnu-linux --class gnu --class os {
insmod part_msdos
insmod ext3
insmod jfs
set root='(hd0,msdos1)'
# search --no-floppy --fs-uuid --set=root 0748915f-7bbe-4450-bf0a-a382d08aee3f
linux /boot/isolinux/linux24 root=/dev/sda1 ro lang=us toram noeject frugal
initrd /boot/isolinux/minirt24.gz
}
In your menuentry you say it is on sdb8 - but in your kernel line you are telling grub to look in sda1 - try changing that to where your DSL is.