i download solaris10 aparc from sun website,and copy cd with nero.
when i run:
# ./setup_install_server /home/ntserver/solaris10sparc
ERROR: /cdrom/sol_10_305_sparc/Solaris_10/Tools/Boot is not a valid install boot image
Check that boot image is valid, or use [-t]
to specify a valid boot image.

this boot file look like error?
# pwd
/cdrom/sol_10_305_sparc/Solaris_10/Tools
# ls -l
total 225
lrwxrwxrwx 1 root other 11 Jan 23 2005 Boot -> ../../../s1
-rwxr-xr-x 2 root bin 66393 Jan 10 2005 add_install_client
-rwxr-xr-x 2 root sys 1325 Jan 10 2005 dial
-rwxr-xr-x 2 root bin 19074 Jan 10 2005 rm_install_client
-rwxr-xr-x 2 root bin 26907 Jan 10 2005 setup_install_server

boot should be directory? or link file?

Probably one of:
- your CD is corrupted (check the iso, check the system messages with dmesg)
- you have mounted the CD manually (unmount it and use vold instead)
- vold hasn't mounted all the slices correctly, restart vold:
/etc/init.d/volmgt stop
/etc/init.d/volmgt start