why cant i do a newfs?

what do you make of this ??
all I want to do is newfs a slice of disk.....

# uname -a
SunOS myhost 5.10 Generic_120011-14 sun4u sparc SUNW,Sun-Fire-V240
# cat /etc/release
Solaris 10 8/07 s10s_u4wos_12b SPARC
Copyright 2007 Sun Microsystems, Inc. All Rights Reserved.
Use is subject to license terms.
Assembled 16 August 2007
#
# newfs /dev/dsk/c1t2d0s0
newfs: /dev/rdsk/c1t2d0s0 last mounted as /backup/OS
newfs: construct a new file system /dev/rdsk/c1t2d0s0: (y/n)? y
/dev/dsk/c1t2d0s0 is normally mounted on /backup/OS according to /etc/vfstab. Please remove this entry to use this device.
# echo $?
2

newfs is telling you why. You need to remove/comment the entry in vfstab.

never had to do that in other versions of solaris and was hoping that there may have been an easer/better way.....

Yes, just comment out the entry.

edit: sorry, that was already suggested.

Yes, it's actually quite annoying. Format also does similar things these days. I must remember to write an RFE for a "force" option for all the disk/fs commands.