zfs boot size

[Randy Bush]

> We always put swap directly after it so if a resize is needed its easy
> without and resilvering .

i am an idiot

raid0.dfw.rg.net:/root# gpart backup da0 
GPT 128
1   freebsd-boot         34        128  
2   freebsd-swap        162   33554432  
3    freebsd-zfs   33554594 3873308477  

so something such as

# swapoff
# gpart delete -i 1
# gpart delete -i 2
# gpart add -t freebsd-boot -i 1 -b 40 -s 256
# gpart add -t freebsd-swap -i 2
# some incantation to install zfs boot blocks
# swapon

thanks for clue bat