[root@beautifulmind practice]# mount /mnt/cdrom
mount: /dev/scd0 is not a valid block device

what option did i miss in configuration?

thank you

Actually, here's what I am thinking, and it's just an idea...

If this is a CD burner and you are simply doing scsi emulation, then did you possibly forget the "append" line in lilo?
append="hdb=ide-scsi"
or something similar?

Try adding following line in /etc/lilo.conf
append="hdc=ide-scsi"

Thomas

there's an append line in my lilo.conf..
----
portion of lilo.conf ..
image=/boot/vmlinuz-2.4.18
label=failsafe
root=/dev/hda5
initrd=/boot/initrd-2.4.18.img
append="failsafe devfs=nomount hdc=ide-scsi"
read-only

------

[root@beautifulmind root]# mount
/dev/hda5 on / type ext2 (rw,noatime)
none on /proc type proc (rw)
/dev/hda7 on /boot type ext2 (rw,noatime)
none on /dev/pts type devpts (rw,mode=0620)
none on /dev/shm type tmpfs (rw)
/dev/hda11 on /home type ext2 (rw,noatime)
/dev/hda8 on /home/eugene/data type ext2 (rw,noatime)
/dev/hda1 on /mnt/windows type vfat (rw,noexec,gid=501,uid=501,umask=022)
/dev/hda9 on /usr type ext2 (rw,noatime)
/dev/hda10 on /usr/local type ext2 (rw,noatime)

[root@beautifulmind root]# mount /mnt/cdrom
mount: /dev/scd0 is not a valid block device

[root@beautifulmind root]# mount /dev/hdc /mnt/cdrom
mount: /dev/hdc is not a valid block device
[root@beautifulmind root]#

where do i have to check more?
thank you

if i have only one hard driver
my cd becomes hdb
and if had 2 hard, my cd becomes hdc?

Depends,
primary master - hda
primary slave - hdb
secondary master - hdc
secondary slave - hdd

thx
it turned out i didn't enable scsi options when compiling kernel..

Cool, glad you got it fixed.