>[something like this]
>panic: ubc_init: unable to allocate ubc_object

Try this patch.

*** vmparam.h~	Thu Mar  8 05:34:06 2001
--- vmparam.h	Thu Mar  8 05:34:23 2001
***************
*** 91,103 ****
  
  /* XXX max. amount of KVM to be used by buffers. */
  #ifndef VM_MAX_KERNEL_BUF
! #define VM_MAX_KERNEL_BUF	(SEGMENT_LENGTH * 7 / 10)
  #endif
- 
- /*
-  * Override the default pager_map size, there's not enough KVA.
-  */
- #define PAGER_MAP_SIZE		(4 * 1024 * 1024)
  
  #define	VM_PHYS_SIZE		(USRIOSIZE * NBPG)
  
--- 91,98 ----
  
  /* XXX max. amount of KVM to be used by buffers. */
  #ifndef VM_MAX_KERNEL_BUF
! #define VM_MAX_KERNEL_BUF	(SEGMENT_LENGTH * 6 / 10)
  #endif
  
  #define	VM_PHYS_SIZE		(USRIOSIZE * NBPG)