I'd like to zero-fill the partitions/slices in my FreeBSD VMs in order to provide for better compression for archival. For those partitions/slices with file systems the process is no problem for me to figure out.
I know I can turn off the swap space use via
swapoff -a. However, I am uncertain as to whether the swap space has a special structure in FreeBSD and whether I need to reinitialize this structure (like in Linux with
mkswap) after zero-filling the slice using
Can anybody shed light on how I can safely zero-fill the swap space and all partitions such that after shutdown I get the best compression possible?