Can not create slice on a SATA drive

[Xi.Liu]

Hullo,



I have Dell power edge S420 with only one SATA harddrive running FreeBSD
5.3-RELEASE for AMD64 platform and the system is running fine.

The hardrive right now has the following partitions:
-----------------------------------------------------------------------

Disk name:      ad4           Disk name:      ad4
FDISK Partition Editor
DISK Geometry:  9726 cyls/255 heads/63 sectors = 156248190 sectors (76293MB)

Offset       Size(ST)        End     Name  PType       Desc  Subtype
Flags

         0         63         62        -     12     unused        0
        63     112392     112454    ad4s1      7        fat        6
    112455   16579080   16691534    ad4s2      8    freebsd      165
  16691535  139558465  156249999        -     12     unused        0


I am trying to create a slice to use the all the rest unused disk space, but
some how I can save the changes using "sysinstall" 
(see error messages below)
----------------------------------------------------------------------------
----------------------------------------------------------------------------
-------------------------------

DISK Geometry:  9726 cyls/255 heads/63 sectors = 156248190 sectors (76293MB)

Offset       Size(ST)        End     Name  PType       Desc  Subtype
Flags

         0         63         62        -     12     unused        0
        63     112392     112454    ad4s1      7        fat        6    =
    112455   16579080   16691534    ad4s2      8    freebsd      165    =
  16691535  139556655  156248189    ad4s3      8    freebsd      165    =
 156248190       1810  156249999        -     12     unused        0



                  ????????????????? Message ??????????????????
                 ??ERROR: Unable to write data to disk ad4!  ?k
                 ????????????????????????????????????(100%)???x
                 ??               [  OK  ]                   ?j
                  ??????????[ Press enter or space ]??????????


Does anyone know why and how to fix it? The only thing is that  I was not
running "sysinstall" from the a local console, but from remote telnet window
as root. Do I have to run sysinstall from local console?


Thanks
Xi