unable to boot from an external firewire disk

88[root@c199-13 /var/root]#uname -a
Darwin c199-13.eecs.berkeley.edu 8.5.0 Darwin Kernel Version 8.5.0: Sun Jan 22 10:38:46 PS\
T 2006; root:xnu-792.6.61.obj~1/RELEASE_PPC Power Macintosh powerpc

If I push option at startup, external firewire partitions don't show.
If I try /Applications/"System Preferences"
I get in console.log :

Can't find IOService for disk1s6
Could not determine if partition needs booter
Error while updating booter for /dev/disk1s7
Can't find IOService for disk1s6
Could not determine if partition needs booter
Can't get Open Firmware information
Can't set Open Firmware
Error running bless. Returned error 3
2006-04-11 17:36:19.510 System Preferences[560] Error setting the Startup Disk.

Thank you very much.
If you have any questions, please don't hesitate to contact me.
  Thanks, G Camij Toschian,
gct (at) cory dot eecs.berkeley.edu, EECS Instructional & Electronics Support Group
  / 386 Cory Hall / 510 643-6138
http://inst.eecs.berkeley.edu/~gct
Please don't send me attachment files.
Please include a meaningful subject in your email.

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Received on Tue Apr 11 18:18:06 2006