[CentOS] mkswap, lvm and bootbits sectors

Hello,

I am confused by a warning from mkswap :

When making a swap on a LVM volume, I see the following warning :
  mkswap: /dev/vg_SDB1/swap_test6_64: warning: don't erase bootbits
  sectors on whole disk. Use -f to force.
  Setting up swapspace version 1, size = 1048572 KiB

Is it safe to use mkswap -f in this case ?
(If that matters, the swap is intended for a virtual machine, and 
the host where I am using mkswap is a CentOS-6 server.)

Thanks,

-- 
Philippe Naudin